Multi-controller security network

ABSTRACT

A security network containing multiple controller functions that communicate using wireless communications. The controller functions are contained within base units. One controller function may be the master controller. Other controller functions may receive a copy of the configuration data contained within the master controller. If the master controller fails, another controller function may become the master controller. The controller functions may use encryption keys to encrypt and/or authenticate communications. Some base units may contain a telecommunications interface. Controller units may relay communications between themselves to reach a telecommunications interface. Controller functions located in different buildings may communicate. Controller functions may each receive wireless communications from a transponder and combine the received communications to reduce errors.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation-in-part of U.S. applicationSer. No. 10/602,854, titled “RFID Reader for a Security Network,” filedon Jun. 25, 2003 by the inventor of the present application, which isitself a continuation-in-part of U.S. application Ser. No. 10/423,887,titled “RFID Based Security Network,” filed on Apr. 28, 2003 by theinventor of the present application, which is itself acontinuation-in-part of U.S. application Ser. No. 10/366,316, titled“RFID Reader for a Security System,” filed on Feb. 14, 2003 by theinventor of the present application, which is itself acontinuation-in-part of U.S. application Ser. No. 10/356,512 (now issuedas U.S. Pat. No. 6,888,459), titled “RFID Based Security System,” filedon Feb. 3, 2003 by the inventor of the present application. This patentapplication is further cross referenced to the following patentapplications, all filed on Feb. 14, 2003 by the inventor of the presentapplication: “Communications Control in a Security System,” U.S.application Ser. No. 10/366,320; “Device Enrollment in a SecuritySystem,” U.S. application Ser. No. 10/366,335; “Controller for aSecurity System,” U.S. application Ser. No. 10/366,334; and “RFIDTransponder for a Security System,” U.S. application Ser. No.10/366,317. All of the foregoing cross-referenced patent applicationsare incorporated by reference into this present patent application.

TECHNICAL FIELD

The present invention relates generally to security networks and, moreparticularly, to a security network containing multiple controllerfunctions that communicate using wireless communications.

BACKGROUND OF THE INVENTION

Security systems and home automation networks are described in numerouspatents, and have been in prevalent use for over 40 years. In the UnitedStates, there are over 14 million security systems in residential homesalone. The vast majority of these systems are hardwired systems, meaningthe keypad, system controller, and various intrusion sensors are wiredto each other. These systems are easy to install when a home is firstbeing constructed and access to the interiors of walls is easy; however,the cost increases substantially when wires must be added to an existinghome. On average, the security industry charges approximately $75 peropening (i.e., window or door) to install a wired intrusion sensor (suchas a magnet and reed switch), where most of this cost is due to thelabor of drilling holes and running wires to each opening. For thisreason, most homeowners only monitor a small portion of their openings.This is paradoxical because most homeowners actually want securitysystems to cover their entire home.

In order to induce a homeowner to install a security system, manysecurity companies will underwrite a portion of the costs of installinga security system. Therefore, if the cost of installation were $1,500,the security company may only charge $500 and then require the homeownerto sign a multi-year contract with monthly fees. The security companythen recovers its investment over time. Interestingly enough, if ahomeowner wants to purchase a more complete security system, the revenueto the security company and the actual cost of installation generallyrise in lockstep, keeping the approximate $1,000 investment constant.This actually leads to a disincentive for security companies to installmore complete systems—they use up more technician time withoutgenerating a higher monthly contract or more upfront profit.Furthermore, spending more time installing a more complete system forone customer reduces the total number of systems that any giventechnician can install per year, thereby reducing the number ofmonitoring contracts that the security company obtains per year.

In order to reduce the labor costs of installing wired systems intoexisting homes, wireless security systems have been developed in thelast 10 to 20 years. These systems use RF communications for at least aportion of the keypads and intrusion sensors. Typically, a transceiveris installed in a central location in the home. Then, each opening isoutfitted with an intrusion sensor connected to a small battery-poweredtransmitter. The initial cost of the wireless system can range from $25to $50 for each transmitter, plus the cost of the centrally locatedtransceiver. This may seem less than the cost of a wired system, but infact the opposite is true over a longer time horizon. Wireless securitysystems have demonstrated lower reliability than wired systems, leadingto higher service and maintenance costs. For example, each transmittercontains a battery that drains over time (perhaps only a year or two),requiring a service call to replace the battery. Further, in largerhouses, some of the windows and doors may be an extended distance fromthe centrally located transceiver, causing the wireless communicationsto intermittently fade out. In fact, the UL standard for wirelesssecurity systems allows wireless messages to be missed for up to 12hours before considering the missed messages to be a problem. Thisimplies an allowable error rate of 91%, assuming a once-per-hoursupervisory rate.

These types of wireless security systems generally operate under 47 CFR15.231 (a), which places limits on the amount of power that can betransmitted. For example, at 433 MHz, used by the wireless transmittersof one manufacturer, an average field strength of only 11 mV/m ispermitted at 3 meters (equivalent to approximately 36 microwatts). At345 MHz, used by the wireless transmitters of another manufacturer, anaverage field strength of only 7.3 mV/m is permitted at 3 meters(equivalent to approximately 16 microwatts). Control or supervisorytransmissions are only permitted once per hour, with a duration not toexceed one second. If these same transmitters wish to transmit dataunder 47 CFR 15.231 (e), the average field strengths at 345 and 433 MHzare reduced to 2.9 and 4.4 mV/m, respectively. The current challenges ofusing these methods of transmission are discussed in various patents,including U.S. Pat. No. 6,087,933, U.S. Pat. No. 6,137,402, U.S. Pat.No. 6,229,997, U.S. Pat. No. 6,288,639, and U.S. Pat. No. 6,294,992.

In either wired or wireless conventional security systems, additionalsensors such as glass breakage sensors or motion sensors are anadditional cost beyond a system with only intrusion sensors. Each glassbreakage or motion sensor can cost $30 to $50 or more, not counting thelabor cost of running wires from the alarm panel to these sensors. Inthe case of wireless security systems, the glass breakage or motionsensor can also be wireless, but then these sensors suffer from the samedrawback as the transmitters used for intrusion sensing—they are batterypowered and therefore require periodic servicing to replace thebatteries and possible reprogramming in the event of memory loss.

Because existing wireless security systems are not reliable and wiredsecurity systems are difficult to install, many homeowners foregoself-installation of security systems and either call professionals ordo without. It is interesting to note that, based upon the rapid growthof home improvement chains such as Home Depot and Lowe's, there is alarge market of do-it-yourself homeowners that will attempt carpentry,plumbing, and tile—but not security. There is, therefore, an establishedneed for a security system that is both reliable and capable of beinginstalled by the average homeowner.

Regardless of whether a present wired or wireless security system hasbeen installed by a security company or self-installed, almost allpresent security systems are capable of only monitoring the house forintrusion, fire, or smoke. These investments are technology limited to asubstantially single purpose. There would be a significant advantage tothe homeowner if the security system were also capable of supportingadditional home automation and lifestyle-enhancing functions. There is,therefore, an apparent need for a security system that is actually anetwork of devices serving many functions in the home. It is thereforean object of the present invention to provide a security system for usein residential and commercial buildings that can be self-installed orinstalled by professionals at a much lower cost than present systems.

BRIEF SUMMARY OF THE INVENTION

The present invention is a highly reliable system and method forconstructing a security network, or security system, for a buildingcomprising a network of devices and using a novel approach to designingbase units and transponders to provide the radio link between each of anumber of openings and a controller function capable of causing an alertin the event of an intrusion.

The present invention improves upon the traditional system model andparadigm by providing a security network with reliability exceeding thatof existing wireless security systems, at lower cost than eitherprofessionally installed hardwired systems or wireless security systems.The present invention also allows self-installation, includingincremental expansion, by typical homeowners targeted by the major homeimprovement and electronics retail chains.

Several new marketing opportunities are created for a security networkthat are otherwise unavailable in the market today. First, forprofessional systems sold by major alarm companies, a single customerservice representative may sell the network to a homeowner and theninstall the network in a single visit to the customer's home. This is incontrast to the present model where a salesperson sells the system andthen an installer must return at a later date to drill holes, pullwires, and otherwise install the system. Second, there is a productupgrade available for existing systems whereby the scope of securitycoverage can be increased by adding base units and transponders to anexisting control panel. Third, homeowners may purchase the inventivesystem at a home improvement chain, self-install the system, andcontract for alarm monitoring from an alarm services company. Theoverall system cost is lower, and the alarm services company is notrequired to underwrite initial installation costs, as is presently donetoday. Therefore, the alarm services company can offer monitoringservices at substantially lower prices. Fourth, a new market forapartment dwellers opens up. Presently, very few security systems areinstalled in apartments because building owners are unwilling to permitthe drilling of holes and installation of permanent systems. Apartmentdwellers are also more transient than homeowners and therefore mostapartment dwellers and alarm service companies are unwilling tounderwrite the cost of these systems anyway. The inventive system is notpermanent, nor is drilling holes for hardwiring required. Therefore, anapartment dweller can purchase the inventive security network, use it inone apartment, and then unplug and move the network to another apartmentlater.

The improvements provided by the present invention are accomplishedthrough the following innovations. The first innovation is the design ofa low-cost base unit that can cover an area of a house. Rather than relyon the single centrally located transceiver approach of existingunreliable wireless security systems, the present invention allows theplacement of multiple base units into multiple rooms and areas for whichcoverage is desired. The presence of multiple base units within abuilding provides spatial receiver diversity.

The second innovation is the use of different types of transponders totransmit data from covered openings and sensors. One transponder may usebackscatter modulation. Another transponder may use low power RFcommunications (i.e., an active transmitter).

The third innovation is the permitted use of multiple distributedcontroller functions in the security network. In the present invention,the controller function can be located within any physical embodiment ofa base unit. Therefore, a homeowner or building owner installingmultiple base units will also simultaneously be installing multiplecontroller functions. The controller functions operate in a redundantmode with each other. Therefore, if an intruder discovers and disables asingle base unit containing a controller function, the intruder maystill be detected by any of the remaining installed base unitscontaining controller functions.

The fourth innovation is the optional inclusion of a glass breakage ormotion sensor into the base unit. In many applications, a base unit willlikely be installed into multiple rooms of a house. Rather than requirea separate glass breakage or motion sensor as in conventional securitysystems, a form of the base unit includes a glass breakage or motionsensor within the same integrated package, providing a further reductionin overall system cost when compared to conventional systems.

The fifth innovation is the permitted optional use of the traditionalpublic switched telephone network (i.e., PSTN—the standard home phoneline), the integrated use of a commercial mobile radio service (CMRS)such as a TDMA, GSM, or CDMA wireless network, or the use of a broadbandInternet network via Ethernet or WiFi connection for causing an alert atan emergency response agency such as an alarm service company. Inparticular, the use of a CMRS network provides a higher level ofsecurity, and a further ease of installation. The higher level ofsecurity results from (i) reduced susceptibility of the security systemto cuts in the wires of a PSTN connection, and (ii) optional use ofmessaging between the security system and an emergency response agencysuch that any break in the messaging will in itself cause an alert.

Additional objects and advantages of this invention will be apparentfrom the following detailed description.

BRIEF DESCRIPTION OF THE DRAWING

The invention is best understood from the following detailed descriptionwhen read in connection with the accompanying drawing. It is emphasizedthat, according to common practice, the various features of the drawingare not to scale. On the contrary, the dimensions of the variousfeatures are arbitrarily expanded or reduced for clarity. Included inthe drawing are the following figures:

FIG. 1 shows a base unit communicating with transponders.

FIG. 2 shows an example security network formed with multiple base unitsand transponders.

FIG. 3 shows an architecture of the base unit.

FIG. 4 shows an example security network formed with multiple base unitsand transponders. Various example physical embodiments of base units areshown.

FIG. 5 shows a generalized network architecture of the security network.Various example forms of base units are shown, where some base unitshave included optional functionality.

FIG. 6 shows the distributed manner in which the present invention couldbe installed into an example house.

FIG. 7 shows some of the multiple ways in which a gateway can beconfigured to reach different private and external networks.

FIG. 8 shows some of the multiple ways in which a gateway can beconfigured to reach emergency response agencies and other terminals.

FIG. 9 shows control functions in multiple base units logicallyconnecting to each other. One control function has been designated themaster controller.

FIG. 10 shows an example layout of a house with multiple base units, andthe manner in which the base units may form a network to use wirelesscommunications to reach a gateway.

FIG. 11 shows an example architecture of a passive transponder.

FIG. 12 is a flow chart for a method of providing a remote monitoringfunction.

FIG. 13 shows an example embodiment of a wall-mounted base unit inapproximate proportion to a standard power outlet.

FIGS. 14A and 14B show alternate forms of a passive infrared sensor thatmay be used with the security system.

FIG. 15 shows example embodiments of a smoke detector and a smokedetector collar into which an optional base unit or an optionaltransponder has been integrated.

FIG. 16 shows some of the multiple networks in which gateways can beconfigured to reach a remote processor or server which then connects toone or more emergency response agencies.

FIG. 17 shows security networks in two neighboring residences in whichthe two security networks cooperate with each other to provide alternateways to reach the PSTN, and in which each security network may providealternate communications paths for the base units and transponders ofthe other security network.

FIG. 18 shows multiple gateways connecting to a telephone line and agateway and telephone disconnect devices controlling access fromtelephony devices to the telephone line.

FIG. 19 shows the multiple communications paths that may exist duringthe configuration of the security network or a security system.

FIG. 20 shows multiple gateways connecting to a telephone line andvarious example base units communicating in a security network.

FIG. 21 shows a typical statistical relationship between the number ofbase units in a security network and the probability of any one messagebeing lost (i.e., not received). The exact shape of the curve and valueson the axes are dependent upon a specific installation in a specificbuilding.

FIGS. 22A and 22B show the locations on the base unit where patch ormicrostrip antennas may be mounted so as to provide directivity to thetransmissions.

FIG. 23A shows an example security network where various devices arecommunicating with each other.

FIG. 23B shows an example physical embodiment of a base unit integratedwith an outlet.

FIG. 23C shows an example security network in which messages between theend point devices can be passed through intermediate devices.

FIGS. 24A and 24B show one mechanism by which a base unit may be mountedto a plate, and then mounted to an outlet.

FIGS. 25A and 25B show examples of LED generators and LED detectors thatmay be used as intrusion sensors.

FIG. 26 shows example physical embodiments of a cigarette lighteradaptor for typical use in a vehicle, a remote sounder, and telephonedisconnect devices.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is a highly reliable system and method forconstructing a security network 400, or security system, for use in abuilding, such as a commercial building, single or multifamilyresidence, or apartment. For consistency with the cross-referencedapplications, the term “security system” may be used sometimes, thoughin the context of this present application, the terms “security system”and “security network” 400 shall be considered interchangeable as theyapply to the present invention. The security network 400 may also beused for buildings that are smaller structures such as sheds,boathouses, other storage facilities, and the like. Throughout thisspecification, a residential house will be used as an example whendescribing aspects of the present invention. However, the presentinvention is equally applicable to other types of buildings.

The security network 400 described herein is a set of distributedcomponents that together operate to form a system for detectingintrusion and providing other services to a home or building owner. Thecomponents are arranged in a two-level architecture, described withinthis specification as base units 200 and transponders 100. An examplesecurity network 400 can be formed with as few as one base unit 200 andone transponder 100; however, the security network 400 can also grow toinclude large numbers of both types of devices.

Base units 200 are distinguished by their support for high power RFcommunications, meaning that these devices are capable of generatingcontinuous and/or frequent wireless transmissions, typically at powerlevels of 10 or more milliwatts, and typically operating under FCC rules47 CFR 15.247 or equivalent. Base units 200 are capable of self-forminga network and communicating with each other over large distances, suchas one kilometer or more depending upon exact implementation. Base units200 will generally be AC powered and/or have rechargeable batteries,although this is not a requirement.

Transponders 100 are distinguished by their more limited communicationscapability. Transponders 100 support low power RF communications and/orbackscatter modulation. Low power RF communications means that thesedevices are only permitted to transmit intermittent wirelesscommunications, typically at average power levels of less than 10milliwatts, and typically operating under FCC rules 47 CFR 15.231 or 47CFR 15.249. Transponders 100 are smaller and less expensive than baseunits 200 and do not have access to AC power for either operation orbattery recharging. This lack of access to AC power is one reason forlimiting the communications capability and transmit power level.

A transponder 100 supporting only backscatter modulation may sometimesbe termed a passive transponder 150. Passive transponders 150 cannotindependently generate wireless transmissions and can only respond tocommunications from a base unit 200 using backscatter modulation.Passive transponders 150 based only upon backscatter modulation are lessexpensive, as they do not contain the circuitry to independentlygenerate wireless communications. Passive transponders 150 are eitherbattery powered or obtain their power from the RF transmissions of baseunits 200. Even with a battery, passive transponders 150 can have a lifeof ten or more years as their current drain from the battery isextremely low. Because passive transponders 150 cannot independentlygenerate wireless transmissions, they are not explicitly governed by anyFCC rules and do not require an equipment authorization.

The security network 400 of the present invention may typically include4 elements: an intrusion sensor 600, a transponder 100, a base unit 200,and a controller function 250. FIG. 1 shows this example configurationof the security network 400 with a single base unit 200 communicatingwith several transponders 100, one of which has an associated intrusionsensor 600, one of which has any one of several other sensors 620, and athird which has no sensor. The controller function 250 is logicimplemented in firmware or software and running within one or more baseunits; it is not shown in the diagram, but in this basic configurationthe controller function 250 is contained within the base unit 200.

The security network 400 can be expanded to support multiple base units200. In addition, the security network 400 can communicate with externalnetworks 410 using a base unit 200 containing a telecommunicationsinterface as shown in FIG. 23A. FIG. 23C shows the way in which multiplebase units 200 communicate with each other in the security network 400by self-forming a network using high power RF communications. In FIG.23C some of the base units 200 can directly communicate with each otherand some pairs of base units 200 can only communicate through one ormore intermediate base units. FIG. 6 shows an example of how the logicalarchitecture of FIG. 23C might appear in an example residence.

The security network 400 of the present invention differs significantlyfrom existing products in its highly distributed architecture andtwo-way communications. Instead of being centered around a singlecontrol panel, this invention includes a controller function 250 thatcan be distributed within and among multiple base units 200. Instead ofjust unidirectional wireless transmitters on windows 702 and doors 701,this invention can support bi-directional wireless communicationsbetween a transponder 100 and base unit 200.

Base units 200, once installed, form a security network 400 with eachother as shown in FIGS. 2 and 4. All of the base units 200 in thesecurity network 400 can become aware of and communicate with eachother. As used within the present invention, the term base unit 200shall apply to a family of devices as shown in FIG. 4. There are twodimensions to consider for base units 200: the physical embodiment andthe functional components. Base units 200 can take any one of thefollowing example physical embodiments, among others:

Wall Unit 262

Tabletop Unit 261

Ceiling Unit 590 or 591

Handheld Unit 260

Examples of the physical form factors are shown in FIGS. 4 and 13. Theseexample form factors are not intended to be limited and other physicalform factors are also possible. A wall unit 262 will typically plug intoand be mounted onto an outlet 720. This allows the wall unit 262 to beplaced anywhere within a room, including unobtrusively behind furniture.A tabletop unit 261 will typically be of a form factor and aestheticdesign that allows the unit to sit on a counter or table top and obtainpower from a transformer 267 plugged into a nearby outlet, similar tothe base of a cordless phone. A ceiling unit 590 or 591 will typicallybe in the form factor of a smoke detector 590 or smoke detector collar591, and obtain power from the AC power connections to the smokedetector. A handheld unit 260 will typically be in the form factor of ahandheld cordless telephone with a rechargeable battery.

As shown in FIG. 3, base units 200 can include any of the followingexample functional components:

Transceiver for high power RF communications 204

Receiver or transceiver for low power RF communications 205

Processor 203

Memory (volatile and/or non-volatile) 211

Power supply (AC, rechargeable or non-rechargeable battery) 207 and 208

Antenna system (antenna and interface circuits) 206

Controller function software 250

Cordless phone software 240

Telecommunications interface 220 (example types are shown)

Other functions 221 (example types following)

Keypad interface 265

Display 266

Acoustic transducer 210

Camera 213

Smoke/fire detector interface 212

Every base unit 200 requires a transceiver for high power RFcommunications 204, a processor 203, memory 211, at least one form ofpower supply 207, and an antenna system 206. Every base unit 200 iscapable of forming a network with other base units 200.

Any base unit 200 may further include the controller function 250software. Some base units 200 may not include a controller function 250;this may be because that particular base unit 200 is of a form factor orat a physical location for which it would not be desirable for that baseunit 200 to contain controller function 250 software. Within any onesecurity network 400, and at any one particular time, there willgenerally be only one base unit 200 whose controller function has beenassigned to be the master controller for that security network 400. Allother controller functions 250 within other base units 200 willgenerally be slaved to the master controller 251. The base unit 200whose controller function 250 is presently the master controller 251 maysometimes be termed the master controller 251.

A base unit 200 that includes a telecom interface 220 may sometimes betermed a gateway 300.

The gateway 300 may use any of several example mechanisms for itstelecom interface 220, including a modem 210 for connection to a PSTN403, an Ethernet or WiFi or USB interface 313 for connection to aprivate or public computer network such as the Internet 405, or a CDMAor GSM or TDMA 311 or two-way paging interface 312 for connection to aradio network such as a CMRS 402. For convenience, the term gateway 300may be preceded by an identifier describing the type of telecominterface within the gateway 300. Therefore, a WiFi gateway 520 refersto a gateway 300 containing a WiFi telecom interface 313. It isimportant to note that the term gateway 300 refers to the functionalcapability of a base unit 200 that includes a telecom interface 220; theterm does not necessarily refer to any particular physical embodiment.For example, both a wall unit 262 and a tabletop unit 261 mayfunctionally operate as a gateway 300.

FIG. 5 shows various examples of base units 200 with various addedfunctional components that can be contained and communicate within asecurity network 400. As can be further seen in FIG. 5, differentexample gateways 300 show how the security network 400 can alsocommunicate to networks and systems external to the security network400.

A keypad 265 may be added to a base unit 200 to provide one method foruser interface. A gateway 300 can be provided to enable communicationsbetween the security network 400 and external networks 410 such as, forexample, a security monitoring company 460. The gateway 300 may alsoconvert protocols between the security network 400 and a WiFi network401 or a USB port of a computer 450. A siren driver 551 may be added toa base unit 200 to provide loud noise-making capability. An emailterminal 530 can be added to a base unit 200 to initiate and receivemessages to/from external networks 410 and via a gateway 300. Othersensors 620 may be added to detect fire, smoke, heat, water,temperature, vibration, motion, as well as other measurable events oritems. A camera and/or audio terminal 540 may be added to a base unit200 to enable remote monitoring via a gateway 300. A keyfob 561 may beadded to enable wireless function control of the security network 400.This list of devices that can be added is not intended to be exhaustive,and other types can also be created and added as well.

The distributed nature of the security network 400 is shown in theexample layout in FIG. 6 for a small house. At each opening in thehouse, such as windows 702 and doors 701, for which monitoring isdesired, an intrusion sensor 600 and a transponder 100 are mounted.While identified separately, the intrusion sensor 600 and transponder100 may be physically integrated into the same physical package. In apattern determined by the layout of the house or building into which thesecurity network 400 is to be installed, one or more base units 200 aremounted. Each base unit 200 is in wireless communication with one ormore transponders 100. Each base unit 200 is also in communication withone or more other base units 200, each of which may contain a controllerfunction 250. In general, each base unit 200 is responsible for thetransponders 100 in a predetermined communications range of each baseunit 200. As is well understood to those skilled in the art, the rangeof wireless communications is dependent, in part, upon manyenvironmental factors in addition to the specific design parameters ofthe base units 200 and transponders 100.

According to U.S. Census Bureau statistics, the median size ofone-family houses has ranged from 1,900 to 2,100 square feet (176 to 195square meters) in the last ten years, with approximately two-thirdsunder 2,400 square feet (223 square meters). This implies typical roomsin the house of 13 to 20 square meters, with typical wall lengths ineach room ranging from 3 to 6 meters. It is likely in many residentialhomes that most installed base units 200 will be able to communicatewith transponders 100 in multiple rooms. Therefore, in many cases withthis system it will be possible to install fewer base units 200 thanmajor rooms in a building, creating a security network 400 withexcellent spatial antenna diversity as well as redundancy in the eventof single component failure.

Base units 200 will typically communicate with other base units 200 aswell as passive transponders 150 using frequencies in one or more of thefollowing unlicensed frequency bands: 902 to 928 MHz, 2435 to 2465 MHz,2400 to 2483 MHz, or 5725 to 5850 MHz. These bands permit the use ofunlicensed secondary transmitters, and are part of the bands that havebecome popular for the development of cordless phones and wireless LANnetworks, thereby leading to the wide availability of many low-costcomponents. Three of the FCC rule sets applicable to the presentinvention will be discussed briefly.

Transmissions regulated by FCC rules 47 CFR 15.245 permit fielddisturbance sensors with field strengths of up to 500 mV/m at 3 meters(measured using an average detector function; the peak emission limitmay be up to 20 dB higher). This implies an averaged transmission powerof 75 mW and a peak transmission power of up to 7.5 Watts. Furthermore,transmissions under these rules do not suffer the same duty cycleconstraints as existing wireless security system transmitters operatingunder 47 CFR 15.231 (a). This rule section would only apply when a baseunit 200 is communicating with a passive transponder 150 usingbackscatter modulation, which qualifies the base unit 200 as a fielddisturbance sensor. Prior art wireless security system transmitters arenot field disturbance sensors.

Transmissions regulated by FCC rules 47 CFR 15.247 permit frequencyhopping (FHSS) or digital modulation (DM) systems at transmission powersup to 1 Watt into a 6 dBi antenna, which results in a permitted 4 Wattdirectional transmission. In order for a FHSS device to take advantageof the full permitted power, the FHSS device must frequency hop at leastonce every 400 milliseconds.

Transmissions regulated by FCC rules 47 CFR 15.249 permit fieldstrengths of up to 50 mV/m at 3 meters (measured using an averagedetector function; the peak emission limit may be up to 20 dB higher).This implies an averaged transmission power of 750 μW and a peaktransmission power of up to 75 mW. Unlike 47 CFR 15.247, rule section 47CFR 15.249 does not specify modulation type or frequency hopping.

Most other products using these unlicensed bands are other transienttransmitters operating under 47 CFR 15.247 and 47 CFR 15.249, and soeven though it may seem that many products are available and in use inthese bands, in reality there remains a lot of available space in theband at any one instant in time, especially in residential homes. Mosttransmitters operating under 47 CFR 15.247 are frequency hopping systemswhereby the given spectrum is divided into channels of a specifiedbandwidth, and each transmitter can occupy a given channel for only 400milliseconds. Therefore, even if interference occurs, the time period ofthe interference is brief. In most cases, the base units 200 can operatewithout incurring interference or certainly without significantinterference. In residential homes, the most common products using thesebands are cordless telephones, for which there are no standards (otherthan the 47 CFR 15.247 requirements). Each phone manufacturer uses itsown modulation and protocol format. For data devices, there are severalwell-known standards that use the 2400 to 2483 MHz band, such as 802.11,802.11b (WiFi), Bluetooth, ZigBee (HomeRF-lite), and IEEE 802.15.4,among others.

The present invention has a substantial advantage over theaforementioned products in that many of the physical embodiments of thebase units 200 are fixed. Other products such as cordless phones andvarious data devices usually have at least one handheld, usuallybattery-powered, component. The FCC's Maximum Permitted Exposure (MPE)guidelines, described in OET 65, generally cause manufacturers to limittransmission power of handheld devices to 100 mW or less. Since mostwireless links are symmetrical, once the handheld device (such as thecordless phone) is power limited, any fixed unit (such as the cordlessbase unit) is also limited in power to match the handheld device. Giventhat many of the physical embodiments of the base units 200 of thesecurity network 400 are not handheld, they can use the full powerpermitted by the FCC rules and still meet the MPE guidelines.

As discussed earlier, the preferred type of communication by and betweenbase units 200 is high power RF communication. The invention is notlimiting, and modulation formats and protocols using either FHSS or DMcan be employed. As one example, the high power RF communications canuse Gaussian Frequency Shift Keyed (GFSK) modulation with FHSS. Thisparticular modulation format has already been used quite successfullyand inexpensively for Bluetooth, 802.11, and other data systems toachieve raw data rates on the order of 1 Mbps. In order to take maximumadvantage of the permitted power limits in, for example, the 2400 to2483 MHz band, if a FHSS protocol is chosen, GFSK or otherwise, at least75 hopping channels should be used and if a DM protocol is chosen, aminimum 6 dB bandwidth of 500 KHz should be used. Any designer of asecurity network 400 under this invention can take advantage of thefixed nature of the base units 200 as well as the relatively lowinformation rate requirements to select a modulation format and protocolwith high link margins.

One approach that a designer may consider is a multi-rate design whereinthe high power RF communications use different data rates for differenttypes of data. For example, the day-to-day management of the securitynetwork 400 may involve a low volume of commands and messages. The linkmargins can be improved by implementing a lower data rate. Certain baseunits, such as those including a camera 213, may have high raterequirements that are only required when actually transferring apicture. Therefore, it is possible to design a protocol where the linkruns at a higher rate for certain transfers (i.e., pictures) and a lowerrate for normal communications. It should be noted that most otherproducts in these bands have at least one mobile component and high datarates are required. Therefore, in spite of the presence of otherproducts, the high power RF communications used in the security network400 should achieve higher reliability and range, and lowersusceptibility to interference than other collocated products.

When using high power RF communications, the base units 200 function asa network of nodes. A message originating on one base unit 200 may passthrough intermediate base units 200 before terminating on thedestination base unit, as shown in FIGS. 23C and 10. The base units 200determine their own network topology based upon the ability of each baseunit 200 to reliably transmit and/or receive the transmissions to/fromother base units. As discussed herein, the antennas 206 used in thesebase units 200 may be directional, and therefore it is not alwayscertain that each base unit 200 can directly transmit to and receivefrom every other base unit 200. However, given the power limits andexpected distribution of devices in typical homes and buildings, it canbe generally expected that each base unit 200 can communicate with atleast one other base unit, and that the base units 200 can then form forthemselves a network that enables the routing of a message from any onebase unit 200 to any other base unit 200. Networking protocols are wellunderstood in the art and therefore not covered here. The base units 200described herein typically may use a unique (at least within the homeand neighbor security networks 400) originating and destination addressof each base unit 200 in the header of each message sent in routingmessages within the security network 400.

While the base units 200 use 47 CFR 15.247 rules for their high power RFcommunications with each other, the base units 200 can use both 47 CFR15.245 and 47 CFR 15.247 rules for their wireless communications withpassive transponders 150. Thus, the base units 200 can communicate tothe transponders using one protocol, at a maximum power of 4 W for anylength of time, and then switch to a second protocol, if desired, at amaximum power of 7.5 W to obtain a response from a passive transponder150. While the base unit 200 can transmit at 7.5 W for only 1 ms under47 CFR 15.245, that time period is more than enough to obtain tens orhundreds of bits of data from a transponder 100. The extra permitted 2.7dB of power under 47 CFR 15.245 is useful for increasing the range ofthe base unit 200. In a related function, the base unit 200 can use thelonger transmission times at 4 W to deliver power to the transponders100, as described elsewhere, and reserve the brief bursts at 7.5 W onlyfor data transfer.

Each base unit 200 typically receives communications from one or morepassive transponders 150 using modulated backscatter techniques. To usemodulated backscatter, a base unit 200 transmits a wireless signal to apassive transponder 150. The passive transponder 150 modulates theimpedance of its antenna, thereby altering reflections of the wirelesssignal off its antenna. The base unit 200 then detects the changes inreflected signal. The impedance changes are made using a predeterminedrate whose frequency can be measured by the base unit 200 to distinguishdata bits.

These techniques are very well understood by those skilled in the art,and have been well discussed in a plethora of literature includingpatent specifications, trade publications, marketing materials, and thelike. For example, the reader is directed to RFID Handbook;Radio-Frequency Identification: Fundamentals And Applications, by KlausFinkenzeller, published by John Wiley (1999). U.S. Pat. No. 6,147,605,issued to Vega et al., provides additional material on the design andtheory of modulated backscatter techniques. U.S. Pat. No. 6,549,064,issued to Shanks et al., also provides material on the design and theoryof modulated backscatter techniques. Therefore, this same material isnot covered here. Presently, a number of companies produce miniaturizedchipsets, components, and antennas for base units 200 and transponders100. Many of these chipsets, though designed for the 13.56 MHz band, areapplicable and/or will be available in the higher bands such as thosediscussed here. For example, Hitachi has recently announced themanufacture of its mu-chip, which is a 2.4 GHz transponder 100 measuringonly 0.4 mm square. The most important point here is that the wideavailability of parts permits the designer many options in choosing thespecific design parameters of the base unit 200 and passive transponder150 and therefore the innovative nature of this invention is not limitedto any specific circuit design implementing the wireless link betweenthe base unit 200 and passive transponder 150.

The extensive literature on backscatter modulation techniques and thewide availability of parts does not detract from the innovativeapplication and combination of these techniques and parts to the presentinvention. Most applications of backscatter modulation have been appliedto mobile people, animals, or things that must be authorized, tracked,counted, or billed. No one has previously considered the novelapplication of low cost backscatter modulation components to solve theproblem of monitoring fixed assets such as the windows 702, doors 701,and other structures that comprise the openings of buildings. Allpresent transmitters constructed for conventional wireless securitysystems are more expensive than the backscatter modulation-based designof the present invention because of the additional components requiredfor active transmission. Furthermore, no one has considered the use ofmultiple, distributed low-cost base units 200 with overlapping coverageso that a building's security is not dependent on a single, vulnerable,and historically unreliable central transceiver.

There are several examples of the advantages that the presentbackscatter modulation approach offers versus conventional wirelesssecurity systems. Conventional wireless security systems limit statusreporting by transmitters to times even longer than the FCC restrictionof once per hour in order to conserve the battery in the transmitter.The backscatter modulation approach herein does not have the samebattery limitation because of the modulated backscatter design.Conventional wireless security systems are subject to both falsepositive and false negative indications because centrally locatedtransceivers have difficulty distinguishing noise from real signals. Thecentral transceiver has little control over the time of transmission bya transmitter and therefore must evaluate every signal, whether noise,interference, or real transmission. This is made more difficult becausethe conventional central transceivers are not always located centrallyin the house. Professional installers generally hide these centraltransceivers in a closet or similar enclosure to prevent an intruderfrom easily spotting the central transceivers and disabling them. Eachwall or door through which signals must pass to reach a centraltransceiver can typically cause a loss of up to 10 dB in signal power.In contrast, the backscatter modulation approach places all of thetransmission control in the master controller 251 and base unit 200. Thebase unit 200 only looks for a return response during a read. Thereforethe base unit 200 can be simpler in design.

Some centralized transceivers attempt to use diversity antennas toimprove their reliability; however, these antennas are separated only bythe width of the packaging, which is frequently much less than onewavelength of the chosen frequency (i.e., 87 cm at 345 MHz and 69 cm at433 MHz). As is well known to those skilled in the art of wireless,spatial diversity of antennas works best when the antennas are separatedby more than one wavelength at the chosen frequency. With the presentinvention, base units 200 are separated into multiple rooms, creatingexcellent spatial diversity and the ability to overcome environmentaleffects such as multipath and signal blockage. Multipath and signalblockage are effects of the RF path between any transmitter andreceiver. Most cellular systems use diversity antennas separated bymultiple wavelengths to help overcome the effects of multipath andsignal blockage. Under the present invention, in most installationsthere will be multiple base units 200 in a building. There willtherefore be an independent RF path between each base unit 200 and eachtransponder 100. The master controller 251 may sequence transmissionsfrom the base units 200 so that only one base unit 200 is transmittingat a time. Besides reducing the potential for interference, this allowsthe other base units 200 to listen to both the transmitting base unit200 and the subsequent response from the transponders. If the RF pathbetween the transmitting base unit 200 and the transponder 100 issubject to some form of multipath or signal blockage, it is possible andeven highly probable that one of the remaining base units 200 is capableof detecting and interpreting the signal. If the transmitting base unit200 is having trouble receiving an adequate response from a particulartransponder 100, the master controller 251 may then poll the remainingbase units 200 to determine whether the response was received by any ofthem.

One major design advantage of the present invention versus all otherapplications of backscatter modulation is the fixed and staticrelationship between each base unit 200 and the transponders. While RFIDreaders for other applications must include the complexity to deal withmany simultaneous tags in the read zone, tags moving rapidly, or tagsonly briefly in the read zone, the present invention can take advantageof the controlled static relationship in the following ways.

-   -   While there may be multiple transponders 100 in the read zone of        each base unit, the base unit 200 can poll each transponder 100        individually, preventing collisions or interference. In        addition, because each transponder 100 is responding        individually, the base unit 200 can use the expected response        bit sequence to improve the receive processing gain. A specific        transponder 100 is responding at a specific time, and at least a        portion of the response will contain bits in a predetermined        sequence.    -   Because the transponders 100 are fixed, the base unit 200 can        use longer integration times in its signal processing to        increase the reliability of the read signal, permitting        successful reading at longer distances and lower power when        compared with backscatter modulation applications with mobile        tags.    -   Furthermore, the base unit 200 can make changes in specific        frequency while remaining within the specified unlicensed        frequency band, in an attempt to find, for each transponder 100,        an optimal center frequency, given the manufacturing tolerances        of the components in each transponder 100 and any environment        effects that may be creating more absorption or reflection at a        particular frequency. In a similar manner, the base unit 200 can        learn the center frequencies of the marking and spacing bits        modulated by each transponder 100. While these center        frequencies may be nominally known and designed into the        transponder 100, there is likely a significant probability that        the manufacturing process will result in a variation of actual        modulation frequencies. By matching its demodulation process to        each transponder 100, the base unit 200 can improve its signal        processing margin.    -   Because the multiple base units 200 are controlled from a single        master controller 251, the controller function 250 can sequence        the base units 200 in time so that the base units 200 do not        interfere with each other.    -   Because there will typically be multiple base units 200        installed in each home, apartment, or other building, the        controller function 250 can use the excellent spatial diversity        created by the distributed nature of the base units 200 to        increase and improve the reliability of each reading operation.        That is, one base unit 200 can initiate the transmission        sequence, but multiple base units 200 can tune and read the        response from the transponder 100. Thus, the multiple base units        200 can operate as a network of receivers to demodulate and        interpret the response from the transponder 100.    -   Because the transponders 100 are typically static, and because        the events (such as intrusion) that affect the status of the        sensors connected to transponders 100 are relatively slow        compared to the speed of electronics in the base units, the base        units 200 have the opportunity to pick and choose moments of low        quiescent interference from other products in which to perform        their reading operations with maximum signal-to-noise ratio        potential—all without missing the events themselves.    -   Because the path lengths and path loss from each transponder 100        to the base unit 200 are relatively static, the base unit 200        can use different power levels when communicating with each        transponder 100. Lower path losses require lower power to        communicate; conversely the base unit 200 can step up the power,        within the specified limits of the FCC rules, to compensate for        higher path losses. The base unit 200 can determine the lowest        power level to use for each transponder 100 by sequentially        stepping down its transmit power on successive reading        operations until no return signal can be detected. Then the        power level can be increased one or two incremental levels. This        determined level can then be used for successive reading        operations. This use of the lowest necessary power level for        each transponder 100 can help reduce the possibility of        interference while ensuring that each transponder 100 can always        be read.    -   Finally, for the same static relationship reasons, the master        controller 251 and base units 200 can determine and store the        typical characteristics of transmission between each transponder        100 and each base unit 200 (such as signal power,        signal-to-noise ratio, turn on time, modulation bit time, etc.),        and determine from any change in the characteristics of        transmission whether a potential problem exists. Thus, the base        unit 200 can immediately detect attempts to tamper with the        transponder 100, such as partial or full shielding, deformation,        destruction, or removal.

By taking advantage of the foregoing techniques, the base unit 200 ofthe present invention can support a wireless range of up to 30 meterswhen communicating with passive transponders 150, depending upon thebuilding construction materials, placement of each base unit 200 in aroom, and the furniture and other materials in the room which may havecertain reflective or absorptive properties. This range is more thansufficient for the majority of homes and other buildings in the targetmarket of the present security network 400.

Base units 200 may include receivers or transceivers 205 in order tocommunicate with transponders 100 using low power RF communications.Transponders 100 using low power RF communications will typicallytransmit using the 300 to 500 MHz band and will typically be operatingunder FCC rule 47 CFR 15.231. In particular, frequencies at or near 315,319, 345, and 434 MHz have been historically favored for low power RFtransmitters and many components are available for constructingtransponders 100 that operate at these frequencies. As discussedearlier, conventional wireless security systems suffer from limitationscaused by the low power and intermittent nature of the transmissionsfrom transponders operating under this rule section, coupled with thecentral receiver architecture of these conventional systems.

The present invention has a number of design advantages overconventional wireless security systems, even when using transponders 100operating under the limitations of FCC rule 47 CFR 15.231. The followingadvantages apply for a security network 400 wherein the base units 200include receivers or transceivers in order to communicate withtransponders 100 using low power RF communications.

-   -   The security network 400 permits the installation of multiple        base units 200. These base units 200 can be installed in various        rooms of a building, in a neighboring building, or in a nearby        outbuilding. The base units 200 in the security network 400 form        a spatially diverse network of receivers or transceivers. This        spatial diversity provides a significant increase in reliability        when compared with the limited antenna diversity of conventional        wireless security systems. FIG. 21 shows an example curve        relating the number of base units 200 (in the present invention        base units 200 contain the receivers receiving communications        from transponders 100; in conventional systems other terms may        be used for the wireless receivers) to the probability of        message loss in the security network 400. It can be seen that        increasing the number of receivers, especially in a spatially        diverse manner, dramatically decreases the probability of        message loss. Conventional systems will generally experience        losses in the vicinity of point A in FIG. 21, while the security        network 400 can easily operate in the vicinity of point B.    -   The RF propagation path from each transponder 100 to each base        unit 200 is statistically independent, therefore even if signal        blockage, interference, or multipath is affecting one RF        propagation path, there will be a statistically high probability        that the other RF propagation paths will not be simultaneously        experiencing the same problem. Furthermore, there will be a        different path length from each transponder 100 to each base        unit 200, increasing the likelihood that at least one base unit        200 can receive a message transmitted by a transponder 100 with        a sufficient signal-to-noise ratio. Each base unit 200 will        attempt to receive and demodulate the intended transponder 100        message, creating a base unit-specific version of the message.        Furthermore, each base unit 200 may determine certain quality        factors associated with its version of the message. These        quality factors may be based upon received signal strength,        received signal-to-noise or signal-to-interference ratios,        received errors or error detection/recovery codes, or other        similar factors. The versions may differ somewhat based upon the        problems that may have been experienced on each RF propagation        path from the transponder 100 to each base unit 200. Each base        unit 200 may use high power RF communications to send its base        unit-specific version of the message that it received from a        transponder 100 to a controller function 250, and the controller        function 250 may compare portions of the different base        unit-specific versions of the transponder 100 message in order        to determine the most likely correct version of the intended        transponder 100 message. If necessary, the controller function        250 can combine portions of multiple base unit-specific versions        of the message together in order to form or reconstruct the        intended transponder 100 message.    -   Base units 200 belonging to different security networks 400 may        be within wireless communications range of each other. For        example, two neighboring homes or buildings may each have a        security network 400 installed. A base unit 200 in a first        security network 400 in a first residence in FIG. 17 may receive        low power RF communications from a transponder 100 in a second        security network 400 in a second residence 741 in FIG. 17. The        base unit 200 in the first security network 400 may be        configured to use high power RF communications to send its        version of the message that the first base unit 200 received        from the transponder 100 in the second security network 400 to a        controller function 250 in a base unit 200 in the second        security network 400. Thus, nearby security networks 400 may        cooperate with each other in receiving low power RF        communications from transponders 100.    -   Since base units 200 include processors 203 and memory 211, the        base units 200 may also include receivers that incorporate        signal processing gain to improve the reception of low power RF        communications from transponders 100. Conventional wireless        security systems use receivers that attempt to demodulate low        power RF communications on a symbol-by-symbol basis. That is,        the receivers in conventional wireless security systems        demodulate each symbol independently of each other symbol in the        message. Certain symbols may be demodulated correctly while        other symbols may not be demodulated correctly. The base units        200 of the present invention may use signal processing        techniques whereby the base unit 200 may receive multiple        symbols within the message transmitted by the transponder 100        and then compare the multiple symbols against an expected set of        symbols. This process of comparison is sometimes known in the        art as integration or correlation, and the result is an        improvement in message demodulation due to signal processing        gain. The integration may be coherent or incoherent. For an        example message length of 64 bits, coherent integration can        result in a signal processing gain of 10 log 64, or 18 dB. This        means that a base unit 200 can have a receive sensitivity that        is as much as 18 dB better than the receiver in a conventional        wireless security system.

Every base unit 200 will typically support both high power RFcommunications with other base units 200 and communications withtransponders 100. Some base units 200 may support additional functionsas discussed elsewhere. FIG. 3 shows a block diagram of an exampleembodiment of the base unit 200. Typically, the base unit 200 includes amicroprocessor 203, memory 211, unit specific software, RF modulationand receiving circuits 204, an antenna 206, and a power supply 207. Themicroprocessor 203 and RF modulation and receiving circuits 204 may beincorporated as a single chipset or discretely separated.

One manner in which to build a low-cost base unit 200 is to use anintegrated cordless phone chipset combined with a limited number ofadditional components. However, other base units 200 can also be builtusing discrete mixers, filters, amplifiers, etc. that are not integratedinto a single chipset. While FIG. 3 shows only a single antenna 206 forsimplicity, it may be advantageous for the base unit 200 to contain morethan one antenna to provide increased diversity, directivity, orselectivity. When more than one antenna is present, the RF modulationand/or receiving circuits 204 may enable the switching between themultiple antenna elements 206. Alternately, the design may includeseparate RF modulation and/or receiving circuits 204 for each antennaelement. This may help provide greater separation for the transmit andreceive signals. If the base unit 200 is to also include a controllerfunction 250, the microprocessor 203 will also require sufficient memory211 for program and data storage.

Base units 200 can be implemented for use with transponders 100 thatemploy low power RF communications or passive transponders 150 thatemploy backscatter modulation. Within a single security network 400,typically all transponders 100 would commonly use only onecommunications type or the other. Therefore, the RF modulation andreceiving circuits 204 of the base unit 200 should typically reflect theselected communications type for the transponders 100 in the particularsecurity network 400. If the transponders 100 in the security network400 employ low power RF communications, then the RF modulation and/orreceiving circuits must support both high power RF communications 204and low power RF communications 205. If the transponders in the securitynetwork 400 employ backscatter modulation (i.e., they are passivetransponders 150), then the RF modulation and/or receiving circuits willtypically be required to only support high power RF communications 204.

If battery backup is desired, the packaging of the base unit 200 alsopermits the installation of a battery 208 for backup purposes in casenormal power supply 207 is interrupted. It is also possible to constructan embodiment without a local power supply 207 and that runs entirelyfrom a battery 208. One such embodiment may take a physical form similarto a cordless phone handset 260.

The inventive base unit 200 need not be limited to any particularmodulation scheme for either its high power RF communications or supportfor backscatter modulation by a passive transponder 150. The choice ofthe microprocessor 203, RF modulation and/or receiving circuits 204, andantenna 206 may be influenced by various modulation considerations. Forexample, because the base unit 200 and transponder 100 may operate inone of the shared frequency bands allocated by the FCC, these devices,as do all Part 15 devices, are required to accept interference fromother Part 15 devices. It is primarily the responsibility of the baseunit 200 to manage communications with the transponder 100, andtherefore the following are some of the capabilities that may beincluded in the base unit 200 to mitigate interference.

Passive transponders 150 use backscatter modulation, which alternatelyreflects or absorbs the signal radiated by the base unit 200 in order tosend its own data back. Therefore, a passive transponder 150 willautomatically follow, by design, the specific frequency and modulationused by the base unit 200. This is a significant advantage versusconventional wireless security system transmitters, which can onlytransmit at a single modulation scheme with the carrier centered at asingle frequency. If interference is encountered at or near that singlefrequency, these transmitters of conventional wireless security systemshave no ability to alter their transmission characteristics to avoid ormitigate the interference.

A base unit 200 can be implemented to support any of the followingmodulation schemes, though the present invention is not limited to justthese modulation schemes. As is well known in the art, there are manymodulation techniques and variations within any one modulationtechnique, and designers have great flexibility in making choices inthis area. The simplest is a carrier wave (CW) signal, at a variety offrequency choices within the allowable bandwidth. A CW conveys noinformation from the base unit 200 to a passive transponder 150, butallows a passive transponder 150 to modulate the return signal describedherein. The base unit 200 would typically use another modulation schemesuch as Binary Phase Shift Keyed (BPSK), Gaussian Minimum Shift Keyed(GMSK), Gaussian Frequency Shift Keyed (GFSK) or even on-off keyed (OOK)AM, when sending data to a transponder 100, but can use CW whenexpecting a return signal. The base unit 200 can concentrate itstransmitted power into this CW, permitting this narrowband signal tooverpower a portion of the spread spectrum signal typically used byother devices operating in the unlicensed bands. If the base unit 200 isunsuccessful with CW at a particular frequency, the base unit 200 canshift frequency within the permitted band. As stated, under the presentinvention a passive transponder 150 will automatically follow the shiftin frequency by design. Rather than repeatedly generating CW at a singlefrequency, the base unit 200 can also frequency hop according to anyprescribed pattern. The pattern may be predetermined or pseudorandom.This pattern can be adaptive and can be varied, as needed to avoidinterference.

There may be times when the interference experienced by the base unit200 is not unintentional and not coming from another Part 15 device. Oneway in which a very technically knowledgeable intruder may attempt todefeat the security network 400, or any wireless system, of the presentinvention is by intentional jamming. Jamming is an operation by which amalicious intruder independently generates a set of radio transmissionsintended to overpower or confuse legitimate transmissions. In this case,the intruder would likely be trying to prevent one or more transponders100 from reporting a detected intrusion to the base unit 200, and thento the master controller 251. Jamming is illegal, of course, under theFCC rules; however, intrusion itself is also illegal. In all likelihood,a person about to perpetrate a crime may not give any consideration tothe FCC rules. Therefore, the base unit 200 may also contain algorithmsthat can determine within a reasonable probability that the base unit200 is being subjected to jamming. For example, if one or more baseunits 200 detect a change in the radio environment, in a relativelyshort predetermined period of time, wherein attempted changes inmodulation schemes, power levels, and other parameters are unable toovercome the interference, the master controller 251 can cause an alertindicating that it is out of communication with one or more transponderswith the likely cause being jamming. This condition can be distinguishedfrom the failure of a single transponder 100 by a simultaneous andparallel occurrence of the change in RF environment, caused by signalsnot following known FCC transmission rules for power, duty cycle,bandwidth, modulation, or other related parameters and characteristics.The alert can allow the building owner or emergency response agency 460to decide upon an appropriate response to the probable jamming.

Many homeowners desire monitoring of their security networks 400 by analarm services company 460. The inventive security network 400 permitsmonitoring as well as access to various external networks 410 through afamily of devices known as gateways 300, each of which permits accessfrom the security network 400 to external devices and networks usingdifferent protocols and physical connections. A gateway 300 is a baseunit 200 with an added telecommunications interface. Each gateway 300 isconfigured with appropriate hardware and software that match theexternal network 410 to which access is desired. As shown in FIGS. 16and 7, examples of external networks 410 to which access can be providedare private Ethernets 401, CMRS 402, PSTN 403, WiFi 404, and theInternet 405. This list of external networks 410 is not meant to belimiting, and appropriate hardware and software can be provided toenable the gateway 300 to access other network formats and protocols aswell. Private Ethernets 401 are those which might exist only within abuilding or residence, servicing local computer terminals 450. If thegateway 300 is connected to a private Ethernet 401, access to theInternet 405 can then be provided through a cable modem 440, DSL 441, orother type of broadband network 442. There are too many suppliers toenumerate here.

A block diagram of the gateway 300 is the same as that of the base unitshown in FIG. 3. Typically, the gateway 300 includes a microprocessor203, memory 211, unit specific software, RF modulation and receivingcircuits 204, an antenna 206, and power supply 207. The microprocessor203 and RF modulation and receiving circuits 204 may be incorporated asa single chipset or discretely separated. The telecommunicationsinterface 220 will vary depending upon the external network to which thegateway 300 is to connect. The gateway 300 will typically communicatewith the base units 200 using high power RF communications.

As shown in FIGS. 16 and 20, the security network 400 permits theinstallation of multiple gateways 300 in a single security network 400,each of which can interface to the same or different external networks410. For example, a second gateway 300 can serve to function as analternate or backup gateway 300 for cases in which the first gateway 300fails, such as component failure, disablement or destruction by anintruder, or loss of power at the outlet where the first gateway 300 isplugged in. If there are multiple gateways installed in a securitynetwork 400, these gateways may be located in different buildings andmay be connected to different networks. For example, a user may installa security network 400 including a gateway 300 in their residence 740and then also place a second gateway 300 in their neighbor's residence741. The first gateway 300 is then connected to one telephone line andthe second gateway 300 is then connected to the neighbor's telephoneline, as shown in FIG. 17.

Homeowners and building owners generally desire one or two types ofalerts in the event that an intrusion is detected. First, an audiblealert may be desired whereby a loud siren 551 is activated both tofrighten the intruder and to call attention to the building so that anypassers-by may take notice of the intruder or any evidence of theintrusion. However, there are also scenarios in which the building ownerprefers the so-called silent alert whereby no audible alert is made soas to lull the intruder into believing he has not been discovered andtherefore may still be there when law enforcement personnel arrive. Thesecond type of alert involves messaging an emergency response agency460, indicating the detection of an intrusion and the identity of thebuilding, as shown in FIGS. 8 and 16. The emergency response agency 460may be public or private, depending upon the local customs, and so, forexample, may be an alarm services company 460 or the city policedepartment 460.

The gateway 300 of the inventive system supports the second type offoregoing alert by preferably including different telecommunicationsinterfaces 220, or modules, such as, for example, a modem module 310,wireless module 311 and 312, WiFi module 313, or Ethernet module 313.The modem module 310 is used for connection to a public switchedtelephone network (PSTN) 403; the wireless module 311 is used forconnection to a commercial mobile radio service (CMRS) network 402 suchas any of the widely available CDMA, TDMA, or GSM-based 2G, 2.5G, or 3Gwireless networks. The WiFi module 313 is used for connection to privateor public WiFi networks 404; the Ethernet module 313 is used forconnection to private or public Ethernets 401.

Certain building owners will prefer the high security level offered bysending an alert message through a CMRS network 402 or WiFi network 404.The use of a CMRS network 402 or WiFi network 404 by the gateway 300overcomes a potential point of failure that occurs if the intruder wereto cut the telephone wires 431 prior to attempting an intrusion. If thebuilding owner has installed at least two gateways 300 in the system,one gateway 300 may have a wireless module 311/312 installed and asecond may have a modem module 310 installed. This provides theinventive security network 400 with two separate communication paths forsending alerts to the emergency response agency 460 as shown in FIG. 8.By placing different gateways 300 (FIGS. 16 and 20) in very differentlocations in the building, the building owner significantly decreasesthe likelihood that an intruder can discover and defeat the securitynetwork 400.

Any base unit 200, including gateways 300, may include a controllerfunction 250. Conventional alarm panels typically contain a singlecontroller, and all other contacts, motion detectors, etc. are fairlydumb from an electronics and software perspective. For this reason, thealarm panel must be hidden in the house because if the alarm panel werediscovered and disabled, all of the intelligence of the system would belost. The controller function 250 of the present invention may bedistributed through many or all of the base units 200 in the securitynetwork 400, as shown in FIG. 9. The controller function 250 is a set ofsoftware logic that can reside in the processor 203 and memory 211 of anumber of different base units 200 within the security network 400. Ifthe base unit 200 memory is of an appropriate type and size, the memory211 can contain a controller function 250, consisting of both programcode and configuration data. The program code will generally containboth controller function 250 code common to all devices as well as codespecific to the base unit 200 type. For example, a base unit 200 willhave certain device-specific hardware that requires matching code, and agateway 300 may have different device-specific hardware that requiresdifferent matching code.

When multiple base units 200 are installed in a system, the controllerfunctions 250 in the different devices become aware of each other, andshare configuration data and updated program code. The updated programcode can consist of either a later-released version of the program code,or can consist of device-specific code or parameters. For example, if anew type of base unit 200 is developed and then installed into anexisting network, the older base units 200 in the system may requireupdated program code or parameters in order to effectively manage thenew base unit 200.

Each controller function 250 in each device can communicate with allother controller functions 250 in all other base units 200 as shown inFIG. 9. The purpose of replicating the controller function 250 onmultiple base units 200 is to provide a high level of redundancythroughout the entire security network 400, and to reduce or eliminatepossible points of failure (whether component failure, power failure, ordisablement by an intruder). The controller functions 250 implemented oneach base unit 200 perform substantially the same common functions,therefore the chances of system disablement by an intruder are fairlylow.

When there are multiple controller functions 250 installed in a singlesecurity network 400, the controller functions 250 arbitrate amongthemselves to determine which controller function 250 shall be themaster controller 251 for a given period of time. The preferredarbitration scheme consists of a periodic self-check test by eachcontroller function 250, and the present master controller 251 mayremain the master controller 251 as long as its own periodic self-checkis okay and reported to the other controller functions 250 in thesecurity network 400. If the present master controller 251 fails itsself-check test, or has simply failed for any reason or has beendisabled, and there is at least one other controller function 250 whoseself-check is okay, the failing master controller 251 will abdicate andthe other controller function 250 whose self-check is okay will assumethe master controller 251 role. In the initial case or subsequent caseswhere multiple controller functions 250 (which will ideally be the usualcase) are all okay after periodic self-check, then the controllerfunctions 250 may elect a master controller 251 from among themselves byeach choosing a random number from a random number generator, and thenselecting the controller function 250 with the lowest random number.There are other variations of arbitration schemes that are widely known,and any number are equally useful without deducting from theinventiveness of permitting multiple controller functions 250 in asingle security network 400, as long as the result is that in amulti-controller function 250 system, no more than one controllerfunction 250 is the master controller 251 at any one time. In amulti-controller function 250 system, one controller function 250 is themaster controller 251 and the remaining controller functions 250 areslave controllers, keeping a copy of all parameters, configurations,tables, and status but generally not duplicating the actions of themaster controller 251.

In a system with multiple controller functions 250, the security network400 can receive updated program code and selectively update thecontroller function 250 in just one of the base units. If the singlebase unit 200 updates its program code and operates successfully, thenthe program code can be updated in other base units. If the first baseunit 200 cannot successfully update its program code and operate, thenthe first base unit 200 can revert to a copy of older program code stillstored in other base units. Because of the distributed nature of thecontroller functions 250, the security network 400 of the presentinvention does not suffer the risks of conventional alarm panels whichhad only one controller.

Each controller function 250 typically performs some or all of thefollowing major logic activities, although the following list is notmeant to be limiting:

-   -   configuration of the security network 400 whereby each of the        other components are identified, enrolled, and placed under        control of the master controller 251,    -   receipt and interpretation of daily operation commands executed        by the homeowner or building occupants including commands        whereby the system is placed, for example, into armed or        monitoring mode or disarmed for normal building use,    -   communications with other controller functions 250, if present,        in the system including exchange of configuration information        and daily operation commands as well as arbitration between the        controller functions 250 as to which controller function 250        shall be the master controller 251,    -   communications with various external networks 410 for purposes        such as sending and receiving messages, picture and audio files,        new or updated program code, commands and responses, and similar        functions,    -   communications with base units 200 and transponders 100 in the        security network 400 including the sending of various commands        and the receiving of various responses and requests,    -   processing and interpreting data received from the base units        200 including data regarding the receipt of various signals from        the sensors 600 and 620 and transponders 100 within        communications range of each base unit,    -   monitoring of each of the sensors, both directly and indirectly,        to determine, for example, whether a likely intrusion has        occurred, whether glass breakage has been detected, or whether        motion has been detected by a microwave- and/or passive        infrared-based device,    -   deciding, based upon the configuration of the security network        400 and the results of monitoring activity conducted by the        controller function 250, whether to cause an alert or take        another event-based action,    -   causing an alert, if necessary, by some combination of audible        indication such as via a siren device 551, or using a gateway        300 to dial through the public switched telephone network (PSTN)        403 to deliver a message to an emergency response agency 460, or        sending a message through one or more Ethernet 401, Internet        405, and/or commercial mobile radio services (CMRS) 402 to an        emergency response agency 460.

The controller function 250 offers an even higher level of security thatis particularly attractive to marketing the inventive security network400 to apartment dwellers. Historically, security systems of any typehave not been sold and installed into apartments for several reasons.Apartment dwellers are more transient than homeowners, making itdifficult for the dweller or an alarm services company to recoup aninvestment from installing a system. Of larger issue, though, is thesmall size of apartments relative to houses. The smaller size makes itdifficult to effectively hide the alarm panel of conventional securitysystems, making it vulnerable to discovery and then disconnection ordestruction during the pre-alert period. The pre-alert period of anysecurity system is the time allowed by the alarm panel for the normalhomeowner to enter the home and disarm the system by entering anappropriate code or password into a keypad. This pre-alert time is oftenset to 30 seconds to allow for the fumbling of keys, the carrying ofgroceries, the removal of gloves, etc. In an apartment scenario, 30seconds is a relatively long time in which an intruder can search theapartment seeking the alarm panel and then preventing an alert.Therefore, security systems have not been considered a viable option formost apartments. Yet, approximately 35% of the households in the U.S.live in apartments (or other multi-family dwelling units) and theirsecurity needs are not less important than those of homeowners.

The inventive security network 400 may include an additional remotemonitoring function in the controller function 250, which can beselectively enabled at the discretion of the system user. The controllerfunction 250 includes a capability whereby the controller function 250of one base unit 200 can send a message to a designated cooperating baseunit 200 at the time that a pre-alert period begins and again at thetime that the security network 400 has been disabled by the normal user,such as the apartment dweller, by entering the normal disarm code. Thedesignated cooperating base unit 200 may be located anywhere within RFrange of the first base unit 200 such as, for example, anotherapartment, another building, or a secure room within the building.Furthermore, the controller function 250 of one base unit 200 can send adifferent message to the same designated cooperating base unit 200 ifthe normal user enters an abnormal disarm code that signals distress,such as when, for example, an intruder has forced entry by following theapartment dweller home and using a weapon to force the apartment dwellerto enter her apartment with the intruder and disarm the security network400.

In logic flow format, the remote monitoring function operates as shownin FIG. 12 and as described in more detail below, assuming that thefunction has been enabled by the user:

-   -   An intrusion is detected in the building, such as the apartment,    -   the controller function 250 in a first base unit 200 begins a        pre-alert period,    -   the controller function 250 in the first base unit 200 sends a        message to a designated cooperating base unit 200 whereby the        message indicates the identity of the security network 400 and        the transition to the pre-alert state,    -   the designated cooperating base unit 200 begins a timer (for        example 30 seconds or any reasonable period allowing for an        adequate pre-alert time),    -   if the person causing the intrusion is a normal user under        normal circumstances, the normal user will enter or speak the        normal disarm code or password,        -   the controller function 250 in the first base unit 200 ends            the pre-alert period, and enters a disarmed state,        -   the controller function 250 in the first base unit 200 sends            a message to the cooperating base unit 200, whereby the            message indicates the identity of the security network 400            and the transition to the disarm state,    -   if the person causing the intrusion is an intruder who does not        know the disarm code and/or disables and/or destroys the first        base unit 200 containing the controller function 250 of the        security network 400,        -   the timer at the cooperating base unit 200 reaches the            maximum time limit (30 seconds in this example) without            receiving a message from the controller function 250 in the            first base unit 200 indicating the transition to disarm            state,        -   the cooperating base unit 200 may remotely cause an alert            indicating that a probable intrusion has taken place at the            location associated with the identity of the security            network 400,    -   if the person causing the intrusion is an authorized user under        distressed circumstances (i.e., gun to back), the authorized        user enters or speaks an abnormal disarm code or password        indicating distress,        -   the controller function 250 in the first base unit 200 sends            a message to the cooperating base unit 200, whereby the            message indicates the identity of the security network 400            and the use of an abnormal disarm code or password            indicating distress,        -   the cooperating base unit 200 may remotely cause an alert            indicating that an intrusion has taken place at the location            associated with the identity of the security network 400 and            that the authorized user is present at the location and            under distress.

As can be readily seen, this inventive remote monitoring function nowenables the installation of this inventive security network 400 intoapartments without the historical risk that the system can be rendereduseless by the discovery and disablement or destruction by the intruder.With this function enabled, even if the intruder were to disable ordestroy the system, a remote alert could still be signaled because amessage indicating a transition to the disarm state would not be sent,and a timer would automatically conclude remotely at the designatedprocessor. This function is obviously not limited to just apartments andcould be used for any building.

With a wireless module 311 or 312, WiFi module 313, or Ethernet module313 installed, a gateway 300 can also be configured to send either anSMS-based message through the CMRS 402 or an email message through aWiFi network 404 or Ethernet network 401 to the Internet 405 to anyemail address based upon selected user events. For example, anindividual away from home during the day may want a message sent to hispager, wireless phone, or office email on computer 450 if the inventivesecurity network 400 is disarmed at any point during the day when no oneis supposed to be at home. Alternately, a parent may want a message sentwhen a child has returned home from school and disarmed the securitynetwork 400. Perhaps a homeowner has provided a temporary disarm code orpassword to a service company scheduled to work in the home, and thehomeowner wants to receive a message when the work personnel havearrived and entered the home. By assigning different codes or passwordsto different family members and/or work personnel, the owner of thesecurity network 400 can discriminate among the persons authorized todisarm the system. Any message sent, as described herein, can contain anindication identifying the code/password and/or the person that enteredthe disarm code/password. The disarm code/password itself is typicallynot sent for the obvious security reasons, just an identifier associatedwith the code.

The gateway 300 can send or receive updated software, parameters,configuration, or remote commands, as well as distribute these updatedsoftware, parameters, configuration, or remote commands to othercontroller functions 250 embedded in other base units 200. For example,once the security network 400 has been configured, a copy of theconfiguration, including all of the table entries, can be sent to aremote processor 461 for both backup and as an aid to responding to anyreported emergency. If, for any reason, all of the controller functions250 within the security network 400 ever experienced a catastrophicfailure whereby the configuration were ever lost, the copy of theconfiguration stored at the remote processor 461 could be downloaded toa restarted or replacement controller function 250. Certain parameters,such as those used in glass breakage detection, can be downloaded to thecontroller function 250 and then propagated, in this example, to theappropriate glass breakage detection functions that may be containedwithin the system. Therefore, for example, if a homeowner wereexperiencing an unusual number of false alarm indications from a glassbreakage detection function, remote technical personnel could remotelymake adjustments in certain parameters and then download these newparameters to the controller function 250. Additionally, the operatingparameters for new base units 200 can also be downloaded to thecontroller function 250. For example, if a homeowner added a new baseunit 200 to the security network 400 several years after initialinstallation, the parameters for this new type of base unit 200 mightnot exist in the controller function 250. The security network 400 couldobtain the parameters associated with the new base unit 200 from a sitedesignated by the manufacturer.

The controller function 250 can also report periodic status and/oroperating problems detected by the system to the emergency responseagency 460, the manufacturer of the system, or a similar entity. Oneexample of the usefulness of this function is that reports of usagestatistics, status, and/or problems can be generated by an exampleemergency response agency 460 and a copy can be provided to the customeras part of his monthly bill. Furthermore, the usage statistics ofsimilarly situated customers can be compared and analyzed for any usefulpatterns. Technicians at an emergency response agency 460, manufacturerof the system, or similar entity can use any collected data to diagnoseproblems and make changes to the configuration, parameters, or softwareof security network 400 and remotely download these changes to thesecurity network 400. This may eliminate the need for a technician visitto a customer's home or other building.

Any base unit 200 may include an acoustic transducer 210 (shown in FIG.3). The acoustic transducer 210 preferably supports both the receptionof sounds waves and the emission of sound waves such that the acoustictransducer 210 can also be used for functions such as glass breakagedetection, fire alarm detection, two-way audio, the sounding of tonesand alerts, voice recognition, and voice response (i.e., spoken wordresponses to commands). While shown as a single block in FIG. 3, theacoustic transducer 210 can be implemented with a single combinedcomponent or with a separate input transducer (i.e., microphone) andoutput transducer (i.e., speaker and/or piezo).

It is preferred that microprocessor 203 be able to read acoustic datafrom the acoustic transducer 210 in order to analyze the data forspecific patterns. For example, it would be advantageous for themicroprocessor 203 to detect specific speech patterns for use in voicerecognition. Similarly, the microprocessor 203 may look for patternsthat indicate the sound of breaking glass or an alerting smoke detectoror fire alarm. It is also preferred that microprocessor 203 be able tosend acoustic data to the acoustic transducer 210 in order to createsounds for feedback or alerting, or to output pre-stored words for voiceresponse. The memory 211 should ideally contain sufficient data spacefor the storage of both patterns for recognition and output sounds andwords.

An example embodiment of a gateway 300 is a USB gateway 510. The USBgateway 510 includes common characteristics and embodiments with thebase unit 200 including high power RF communications and communicationswith transponders 100. Thus, if a USB gateway 510 has been installed ina room, it may not be necessary for a separate base unit 200 to also beinstalled in a room in order to monitor the transponders 100.

An interface mechanism available for use with the security network 400is a USB gateway 510 that enables a desktop or laptop computer to beused for downloading, uploading, or editing the configuration stored inthe controller functions 250. The USB gateway 510 connects to and mayobtain power from the Universal Serial Bus (USB) port commonly installedin most computers 450 today. The USB gateway 510 can convert signalsfrom the USB port to backscatter modulation or high power RFcommunications with a base unit 200 or gateway 300, thereby providingaccess to the configuration data stored by the controller functions 250.A software program provided with the USB gateway 510 enables the user toaccess the USB gateway 300 510 via the USB port, and display, edit, orconvert the configuration data. In this manner, authorized users have aneasy mechanism to create labels for each of the base units 200, gateways300, and transponders 100. For example, a particular transponder 100 maybe labeled “Living Room Window” so that any alert generated by thesecurity network 400 can identify by label the room in which theintrusion has occurred. The labels created for the various devices canalso be displayed on the display 266 to show, for example, which zonesare in an open or closed state.

Another example embodiment of a base unit 200 is an email device 530.The security network 400 can support an email device 530 that uses highpower RF communications to communicate with the base units 200 andgateways 300. This email device 530, which can take the form of apalm-type organizer or other forms, may typically be used to send andreceive email via the gateway 300. As described earlier, the variousdevices in the security network 400 self form a network, therebyenabling messages to originate on any base unit 200 and terminate on anycapable base unit 200. Therefore, it is not necessary that the emaildevice 530 be near a gateway 300. If necessary, messages can be receivedvia a gateway 300, be routed through multiple base units 200 and thenterminate at the email device 530. The primary advantage of including anemail device 530 in the security network 400 is to provide the homeownera device that is always on and available for viewing. There are agrowing number of wireless phones in use today capable of sending andreceiving SMS messages. The email device 530 provides a convenient,always-on device whereby family members can send short messages to eachother. For example, one spouse can leave a message for another spousebefore leaving work. The functions of the email device may be combinedwith the functions of another device, such as a keypad, toadvantageously form an integrated device.

Another example embodiment of a gateway 300 is a WiFi gateway 520. As analternative to using a USB gateway 510, the security network 400 alsosupports a WiFi gateway 520. WiFi, also known as 802.11b, is becoming amore prevalent form of networking computers. Recently, Intel madeavailable a new chip called Centrino by which many new computers willautomatically come equipped with WiFi support. Therefore, rather thanusing a USB gateway 510 that connects to a port on the computer 450, agateway 300 may include a WiFi module 313. The WiFi gateway 520 canprovide either local access from a local PC 450 (assuming that the localPC supports WiFi) to the security network 400, or alternately from thesecurity network 400 to a public WiFi network 404. It is expected thatin the near future, some neighborhoods will be wired with public WiFinetworks 404. These public WiFi networks 404 will provide anotheralternative access mechanism to the Internet from homes (in addition tocable modems 440 and DSL 441, for example). There may be users,therefore, that may prefer the security network 400 to provide alertsthrough this network rather than a PSTN 403 or CMRS 402 network. In theevent these public WiFi networks 404 become prevalent, then the securitynetwork 400 can offer the email access described above through thesenetworks as well. The WiFi gateway 520 primarily acts as a protocolconverter between the chosen modulation and protocol used within thesecurity network 400 and the 802.11b standard. In addition to theprotocol conversion, the WiFi gateway 520 also provides a software-basedsecurity barrier similar to a firewall to prevent unauthorized access tothe security network 400.

Any base unit 200 may also include a camera 213. A typical type ofcamera 213 may be a miniature camera of the type commonly available inmobile phones and other consumer electronics. Low-cost miniature camerasare widely available for PC and wireless phone use, and formats (i.e.,JPEG) for transmitting pictures taken by these miniature cameras arealso widely known. By recording sequential images taken over a shortperiod of time, a time lapse record may be created. Through one or moreof the gateways 300, the security network 400 can access externalnetworks as well as be accessed through these same networks. Some usersmay find it useful to be able to visually or audibly monitor their homeor building remotely. Therefore, the security network 400 also supportsbase units 200 including cameras 213 and/or audio transducers 210 thatenable a user to remotely see and/or hear what is occurring in a home orbuilding. Each of the base units 200 can be individually addressed sinceeach is typically provided with a unique identity. When a securitynetwork 400 causes an alert, an emergency response agency 460 or anauthorized user can be contacted. In addition to reporting the alert, aswell as the device (i.e., identity of the transponder 100) causing thealert, the security network 400 can be configured to provide picturesand/or audio clips of the activity occurring within the security network400. Base units 200 with cameras 213 and/or audio transducers 210 willbe particularly useful in communities in which the emergency responseagency 460 requires confirmation of intrusion prior to dispatchingpolice.

There are multiple uses for the audio 210 and camera 213 support in thesecurity network 400 in addition to alarm verification by an emergencyresponse agency 460. A caregiver can check in on the status of anelderly person living alone using the audio and/or camera capabilitiesof the security network 400. A family on a trip can check in on theactivities of a pet left at home. The owner of a vacation home canperiodically check in on the property during the winter months when thevacation home is otherwise unoccupied.

Certain base units 200 may be configured with additional memory 211 forthe purpose of storing pictures and/or audio files. By combining withina security network 400 the audio 210 and/or camera 213 capability with aUSB gateway 510 and a local PC, a user can store picture and audio fileson the PC to provide a continuous record of activities in the home. Asan alternative to storing pictures on a local PC, a base unit 200 can beprovided with a large enough memory 211 to contain a file system whereinthe file system stores pictures periodically taken by one or morecameras in the security network 400. One way in which the memory of abase unit 200 can be expanded is through the use of well-known flashmemory. For example, flash memory modules are available in a variety ofpre-packaged formats such as PCMCIA, Compact Flash, or USB, so a baseunit 200 can be implemented to accept modules in these formats. Thepictures and/or audio files in the file system can be accessed later toretrieve pictures taken at particular times. These files can be accessedin a number of ways. If the memory 211 is contained in a removable flashmemory module, the module can be removed and inserted into anotherdevice such as a PC that can read the files. Alternately, the files inthe memory 211 can be accessed through a gateway 300. For example, alocal PC can use a USB gateway 510 or WiFi gateway 520 or an emergencyresponse agency can use a telephone, wireless, or Ethernet-basedconnection.

One advantageous base unit 200 in which a camera 213 can be included isa base unit 200 built into the physical form of a smoke detector 590 ora smoke detector collar 591 as shown in FIG. 15. Since smoke detectorsare generally mounted on ceilings, the inclusion of camera 213capability into a ceiling-mounted base unit 200 built into the physicalform of a smoke detector 590 or smoke detector collar 591 will providethe camera 213 with a wide angle of view with little likely viewingobstruction. A base unit 200 built into the physical form of a smokedetector 590 can include smoke, fire, or CO detection capability 212.The detection technology for smoke, fire, and/or CO is widely known andavailable. A base unit 200 built into the physical form of a smokedetector collar 591 would likely not require smoke, fire, or COdetection 212 capability since the state of the attached smoke, fire, orCO can be detected by the base unit 200.

The inventive security network 400 does not require all smoke detectors590 installed in a home to include a base unit 200 as defined in thisspecification. Certain manufacturers, such as Firex for example, alreadyprovide families of low-cost smoke detectors that have a wiredcommunications capability; that is, if one smoke detector detects smokeand causes an audible alert, all smoke detectors that are wired to thedetecting smoke detector also cause an audible alert. Using the presentinvention, one of the example Firex smoke detectors can be replaced witha base unit 200 of the inventive security network 400, and if any of theFirex family of smoke detectors causes an alert and sends communicationsvia the standard Firex wired communications, the base unit 200 of theinventive security network 400 will receive the same communications asall Firex smoke detectors on the same circuit, and the inventivesecurity network 400 can cause its own alert using its own audiblecapability and/or any gateway 300 installed in the inventive securitynetwork 400. This ability to convert the wired communications from anexisting example Firex network of smoke detectors into appropriatecommunications within the inventive security network 400 obviates theneed for a user to replace all of the smoke detectors in a home wheninstalling an inventive security network 400. While this example hasbeen given using smoke detectors, it is understood that this example isextensible to fire detectors, carbon monoxide (CO) detectors, and othersimilar detection devices typically used in residential and commercialbuildings.

If the designer does not wish to design a base unit 200 includingsmoke/fire/CO detect capability 212, then the designer can place thebase unit 200 functionality into a smoke detector collar 591 that itplaced between an example smoke/fire/CO detector 590 and the mountingplate 592 attached to the ceiling 704. An AC-powered smoke detectorusually requires that an electrical box be installed into the ceiling704. The mounting plate 592 is attached to the electrical box in theceiling 704 and a connector protrudes from the electrical box. Thesmoke/fire/CO detector 590 is then typically connected to the connector,and then snapped onto the mounting plate 592. Under the presentinvention, a smoke detector collar 591 can be placed between themounting plate 592 and the smoke/fire/CO detector 590. The smokedetector collar 591 can provide the physical volume to contain the baseunit 200 functionality as well as intercept the AC power and thecommunications wire that are contained in the connector protruding fromthe electrical box. By intercepting and detecting the state of thecommunications wire, the base unit 200 can detect any changes in state,such as the signaling of an alert. Rather than intercepting thecommunications wire, or in the case of a sensor that does not include aseparate communications wire, the base unit 200 can also sense the audiosignal typically put out by an example smoke/fire/CO detector 590. Theseaudio signals are generally designed to generate audio power ofapproximately 85 dB at 10 feet in various predetermined and distinctivepatterns. The base unit 200 can include an appropriate audio transducer210 that can sense the presence or absence of the volume and/ordistinctive pattern of the audio output by the smoke/fire/CO detector590. In any of the example cases, when the base unit 200 detects analert state being signaled by an example smoke/fire/CO detector 590, thebase unit 200 can send communications to the master controller 251 inthe security network 400. The security network 400 can then send analert to an emergency response agency 460 or take any otherpredetermined action configured in the security network 400 by the enduser.

Note that while smoke detectors and Firex have been used as examples,other types of sensors and other brands/manufacturers can be substitutedinto this specification without detracting from the inventive nature. Itis also not required that full base unit 200 functionality be placedinto the smoke/fire/CO detector 590 or smoke detector collar 591. If nocamera 213 or audio 210 capability is desired, then a transponder 100can be implemented in the smoke/fire/CO detector 590 or smoke detectorcollar 591 instead of a base unit 200. In FIG. 15, both the base unit200 and transponder 100 are shown with dashed lines to show the optionalchoices that can be made.

The base unit 200 can include several options that increase both thelevel of security and functionality in the inventive security network400. One option enhances the base unit 200 to include an acoustictransducer 210 capable of receiving and/or emitting sound waves thatenables a glass breakage detection capability in the base unit 200.Glass breakage sensors have been widely available for years for bothwired and wireless conventional security networks 400. However, they areavailable only as stand-alone sensors typically selling for $30 to $50or more. Of course, in a hardwired system, there is also the additionallabor cost of installing separate wires from the alarm panel to thesensor. The cost of the sensors generally limits their use to just a fewrooms in a house or other building. The cost is due in part to the needfor circuits and processors dedicated to just analyzing the sound waves.

Since the base unit 200 already contains a power supply 207 and aprocessor 203, the only incremental cost of adding the glass breakagedetection capability is the addition of the acoustic transducer 210 andthe software to analyze sound patterns for any of the distinctivepatterns of breaking glass. With the addition of this option, glassbreakage detection can be available in every room in which a base unit200 has been installed.

Glass breakage detection is performed by analyzing received sound wavesto look for certain sound patterns distinct in the breaking of glass.These include certain high-frequency sounds that occur during the impactand breaking of the glass and low frequencies that occur as a result ofthe glass flexing from the impact. The sound wave analysis can beperformed by any number of widely known signal processing techniquesthat permit the filtering of received signals and determination ofsignal peaks at various frequencies over time.

One advantage of the present invention over conventional stand-aloneglass breakage sensors is the ability to adjust parameters in the field.Because glass breakage sensors largely rely on the receipt of audiofrequencies, they are susceptible to false alarms from anything thatgenerates sounds at the right combination of audio frequencies.Therefore, there is sometimes a requirement that each glass breakagesensor be adjusted after installation to minimize the possibility offalse alarms. In some cases, no adjustment is possible in conventionalglass breakage detection devices because algorithms are permanentlystored in firmware at the time of manufacture. Because the glassbreakage detection of the present invention is performed by the baseunits 200, which include or are in communication with a controllerfunction 250, the controller function 250 can alter or adjust parametersused by the base unit 200 in glass breakage detection. For example, thecontroller function 250 can contain tables of parameters, each of whichapplies to different building construction materials or window types.The user can select the appropriate table entry during systemconfiguration, or select another table entry later after experience hasbeen gained with the installed security network 400. Furthermore, thecontroller function 250 can contact an appropriate database via agateway 300 that is, for example, managed by the manufacturer of thesecurity network 400 to obtain updated parameters. There is, therefore,significant advantage to this implementation of glass breakagedetection, both in the cost of device manufacture and in the ability tomake adjustments to the processing algorithms used to analyze the soundwaves.

In a manner similar to glass breakage detection above, the receivedsound waves can be analyzed to look for certain (usually very highdecibel) sound patterns distinct in alerting smoke detectors, firealarms, carbon monoxide detectors, and similar local alerting devices.When one or more base units 200 detect the distinct sound patterns fromany of these local alerting devices, the controller function 250 cansend an appropriate message via a gateway 300 to an emergency responseagency 460.

The addition of the acoustic transducer 210, with both sound input andoutput capability, to the base unit 200 for the glass breakage optionalso allows the base unit 200 to be used by an emergency response agency460 as a distributed microphone to listen into the activities of anintruder. Rather than analyzing the sound waves, the sound waves can bedigitized and sent to the gateway 300, and then by the gateway 300 tothe emergency response agency 460. After the gateway 300 has sent analert message to the emergency response agency 460, the audio transducercan be available for use in an audio link. This two-way audio capabilitythrough the acoustic transducer 210 can be useful for more than justlistening by an emergency response agency 460. Parents who are not homecan listen into the activities of children who might be home. Similarly,a caregiver can use the two-way audio to communicate with an elderlyperson who might be living alone.

In a similar manner, the base unit 200 can contain optional algorithmsfor the sensing of motion in the room. Like glass breakage sensors,conventional motion sensors are widely available as stand-alone devices.Conventional motion sensors suffer from the same disadvantages cited forstand-alone glass breakage sensors, that is they are typicallystand-alone devices requiring dedicated processors, circuits, andmicrowave generators. However, the base unit 200 already contains all ofthe hardware components necessary for generating and receiving the radiowave frequencies commonly using in detecting motion; therefore, the baseunit 200 only requires the addition of algorithms to process the signalsfor motion in addition to performing its reading of the transponders100. Different algorithms are available for motion detection atmicrowave frequencies. One such algorithm is Doppler analysis. It is awell-known physical phenomenon that objects moving with respect to atransmitter cause a reflection with a shift in the frequency of thereflected wave. While the shift is not large relative to the carrierfrequency, it is easily detectable. Therefore, the base unit 200 canperform as a Doppler radar by the rapid sending and receiving of radiopulses, with the subsequent measurement of the reflected pulse relativeto the transmitted pulse. People and animals walking at normal speedswill typically generate Doppler shifts of 5 Hz to 50 Hz, depending onthe speed and direction of movement relative to the base unit 200antenna 206. The implementation of this algorithm to detect the Dopplershift can, at the discretion of the designer, be implemented with adetection circuit or by performing signal analysis using the processorof the base unit 200. In either case, the object of the implementationis to discriminate any change in frequency of the return signal relativeto the transmitted signal for the purpose of discerning a Doppler shift.The base unit 200 is capable of altering its transmitted power to varythe detection range of this motion detection function.

These motion-detection functions can occur simultaneously with thereading of passive transponders 150. Because the passive transponders150 are fixed relative to the base units 200, no unintended shift infrequency will occur in the reflected signal. Therefore, for eachtransmitted burst to a passive transponder 150, the base unit 200 cananalyze the return signal for both receipt of data from the passivetransponder 150 as well as unintended shifts in frequency indicating thepotential presence of a person or animal in motion.

By combining the above functions, the base unit 200 in one examplesingle integrated package may be capable of (i) communicating with otherbase units 200 using high power RF communications, (ii) communicatingwith transponders 100 using low power RF and backscatter wirelesscommunications, (iii) detecting motion via Doppler analysis at microwavefrequencies, (iv) detecting glass breakage and/or high decibel alertsvia sound wave analysis of acoustic waves received via an audiotransducer 210, and (v) providing a two-way audio link to an emergencyresponse agency 460 via an audio transducer 210 and via a gateway 300.This base unit 200 achieves significant cost savings versus conventionalsecurity networks through the avoidance of new wire installation and thesharing of communicating and processing circuitry among the multiplefunctions. Furthermore, because the base units 200 are under the controlof a single master controller 251, the performance of these functionscan be coordinated to minimize interference, and provide spatialdiversity and redundant confirmation of received signals.

A microwave frequency motion detector implemented in the base unit 200is only a single detection technology. Historically, single motiondetection technologies, whether microwave, ultrasonic, or passiveinfrared, all suffer false positive indications. For example, a curtainbeing blown by a heating vent can occasionally be detected by a Doppleranalysis motion detector. Therefore, dual technology motion detectorsare sometimes used to increase reliability—for example by combiningmicrowave Doppler with passive infrared so that motion by a warm body isrequired to trigger an alert. The inventive security network 400provides a novel technique to implement dual technology motion sensingin a room without the requirement that both technologies be implementedinto a single package.

Existing dual technology sensors implement both technologies into asingle sensor because the sensor is only capable of reporting a “motion”or “no motion” condition to the alarm panel. This is fortunate, becausepresent alarm panels are only capable of receiving a “contact closed” or“contact open” indication. Therefore, all of the responsibility foridentifying motion must exist within the single sensor package. Theinventive controller function 250 can receive communications with apassive infrared sensor 570 mounted separately from the base unit 200.Therefore, if in a single room the base unit 200 is detecting motion viamicrowave Doppler analysis and a passive infrared sensor 570 isdetecting the presence of a warm body 710 as shown in FIG. 6, the mastercontroller 251 can interpret the combination of both of theseindications in a single room as the likely presence of a person.

One embodiment of this passive infrared sensor 570 is in the form of alight switch 730 with cover 731 as shown in FIG. 14A. Most major roomshave at least one existing light switch 730, typically mounted at anaverage height of 55″ above the floor. This mounting height is above themajority of furniture in a room, thereby providing a generally clearview of the room. Passive infrared sensors have previously been combinedwith light switches 730 so as to automatically turn on the light whenpeople are in the room. More important, these sensor/switches turn offthe lights when everyone has left, thereby saving electricity that wouldotherwise be wasted by lighting an unoccupied room. Because the primarypurpose of these existing devices is to provide local switching, thedevices cannot communicate with central controllers such as existingalarm panels.

The passive infrared sensor 570 that operates with the inventivesecurity network 400 includes any of high power RF communications, lowpower RF communications, or modulated backscatter communications thatpermit the passive infrared sensor 570 to communicate with one or morecontroller functions 250 in base units 200 and be under control of themaster controller 251. The passive infrared sensor 570 can therefore becombined with a transponder 100 or included in a base unit 200. At thetime of system installation, the master controller 251 is configured bythe user thereby identifying the rooms in which the base units 200 arelocated and the rooms in which the passive infrared sensors 570 arelocated. The master controller 251 can then associate each passiveinfrared sensor 570 with one or more base units 200 containing microwaveDoppler algorithms. The master controller 251 can then require thesimultaneous or near-simultaneous detection of motion and a warm body,such as a person 710, before interpreting the indications as a probableperson in the room.

Because each of the base units 200 and passive infrared sensors 570 areunder control of the master controller 251, portions of the circuitry inthese devices can be shut down and placed into a sleep mode duringnormal occupation of the building. Since conventional motion sensors areessentially stand-alone devices, they are always on and are alwaysreporting a “motion” or “no motion” condition to the alarm panel.Obviously, if the alarm panel has been placed into a disarmed statebecause, for example, the building is being normally occupied, thenthese “motion” or “no motion” conditions are simply ignored by the alarmpanel. But the sensors continue to use power, which although the amountmay be small, it is still a waste of AC or battery power. Furthermore,it is well known in the study of reliability of electronic componentsthat “power on” states generate heat in electronic components, and it isheat that contributes to component aging and possible eventual failure.

The present security network 400 can selectively shut down or at leastslow down the rate of the radiation from the base units 200 when thesecurity network 400 is in a disarmed mode, or if the homeowner orbuilding owner wants the security network 400 to operate in aperimeter-only mode without regard to the detection of motion. Byshutting down the radiation and transmissions used for motion detection,the security network 400 is conserving power, extending the potentiallife of the components, and reducing the possibility of interferencebetween the base unit 200 and other products that may be operating inthe same unlicensed band. This is advantageous because, for example,while people are occupying the building they may be using cordlesstelephones (or wireless LANs, etc.) and want to avoid possibleinterference from the base unit 200. Conversely, when the securitynetwork 400 is armed, there are likely no people in the building, andtherefore no use of cordless telephones, and the base units 200 canoperate with reduced risk of interference from the transmissions fromthe cordless telephones.

In general, a passive transponder 150 has two primary functions: manageits wireless communications and monitor a state change of any attachedmulti-state device. The following description considers the example of apassive transponder 150 used for monitoring intrusions through a windowor door opening. The description can be expanded to include any numberof additional examples, however.

A passive transponder 150, shown in FIG. 11, used with the inventivesecurity network 400 achieves its advantage over wireless transmittersof conventional security systems through its low-cost design. Thepassive transponder 150 contains no active radiation circuitry, andtherefore the design can be limited to low-frequency, low-powercircuitry. A passive transponder 150 can be designed with or without abattery, however the design choice will have an impact on thecorresponding base unit 200 design. If a passive transponder 150 isdesigned without a battery, the base unit 200 will be required totransmit at a higher power level in order to generate a high enoughelectric field to power the passive transponder 150 circuits. The FCCrule sections cited herein permit the transmission of sufficient powerto generate the necessary electric fields, but more expensive circuitryis required in the base unit 200 to achieve the necessary power levels.If a passive transponder 150 is designed with a battery, the base unit200 can be designed using lower-cost circuitry since the transmittedpower will be necessary only for the backscatter modulation to workproperly. The example considers cases of both with or without a batterycontained in the passive transponder 150.

The passive transponder 150 typically engages in one or more of thefollowing types of communications:

receive parameter information,

receive status requests,

send status (which may include the state of an attached multi-statedevice), and

send state change information about an attached multi-state device.

Because the passive transponder 150 uses backscatter modulation forsending communications to a base unit 200, the passive transponder 150can never initiate communications as can a base unit 200. The passivetransponder 150 can only respond to communications from a base unit 200.There are two possible methods by which a base unit 200 can communicatewith a passive transponder 150: (i) listen first, then talk; or (ii)talk first, then listen.

In order to listen, the base unit 200 transmits a signal that thepassive transponder 150 can backscatter modulate. The signal provided bythe base unit 200 may be modulated or may simply be continuous wave. Thecommunications from the passive transponder 150 will include theoriginal signal along with the modulation from the passive transponder150. The base unit 200 will typically subtract the provided signal fromthe communications returned from the passive transponder 150, therebyleaving only the modulation from the passive transponder 150.

When listening first, the base unit 200 first transmits its signal thatenables communications from the passive transponders 150. One or morepassive transponders 150 may elect to backscatter modulate the signal,thereby attempting to send communications to the base unit 200. Afterreceiving communications from the one or more passive transponders 150,the base unit 200 may then talk to the passive transponders 150 if thebase unit 200 has communications to send. In order to talk, the baseunit 200 transmits a message typically using one of the modulationschemes discussed herein. The transmitted message may include a reply tocommunications from the one or more passive transponders 150, or mayinclude a command, parameters, or overhead message. One type of reply isa confirmation of the communications received from the passivetransponder 150. Another type of reply may be that the communicationsfrom the passive transponder 150 failed to be received.

When talking first, the base unit 200 first transmits its message, whichthen may be followed by the transmission of its signal that enablescommunications from the passive transponders 150. By talking first, thebase unit 200 may direct a particular passive transponder 150 tocommunicate in return, or enable any passive transponder 150 with datato send to communicate in return.

Whether or not the passive transponder 150 contains a battery, it ispreferred that the passive transponder 150 conserve power by operatingin a periodic cycle. During a portion of the periodic cycle, it ispreferred that the passive transponder 150 place some or all of itscircuits in a low power or zero power state. For example, if the passivetransponder 150 is designed using CMOS-based circuitry, any clock usedto drive the circuitry can be stopped since CMOS circuits use most oftheir power during clock or signal transitions. During other portions ofthe periodic cycle, sufficient circuitry may be enabled such that thepassive transponder 150 can send communications to or receivecommunications from the base unit 200. It is not required that allpassive transponders 150 within a single security network 400 use thesame periodic cycle. Some may have longer cycles than others. Ifnecessary, the controller function 250 may maintain a table listing eachmanaged passive transponder 150 and its corresponding periodic cycle.

The master controller 251 in a security network 400 will typicallyestablish certain operating parameters, which can vary from installationto installation. One of the parameters may be the periodic cycle onwhich the passive transponders 150 are to operate. These parameters mayvary with the number of active and passive transponders 150 installed ina system, as well as with the present state of the system. For example,if a security network 400 is presently in the disarmed state, the mastercontroller 251 may lengthen the periodic cycle which will cause lessfrequent communications and conserve more power in the transponders. Ifthe security network 400 is presently armed, the periodic cycle may beshortened to enable more frequent communications to ensure the integrityof the system.

Other parameters that the master controller 251 may send to a passivetransponder 150 may include identity information about the securitynetwork 400, identity information for each transponder 100, and keysthat the passive transponder 150 may use for encryption orauthentication in its communication with a base unit 200. In geographicareas where many security networks 400 may be simultaneously operating,the stored identity information may be useful in maintaining the desiredassociations between each security network 400 and its base units 200,transponders 100, and other active and passive transponders 150.

Many forms of the passive transponder 150 will be used to monitor andreport upon the state of an attached sensor. For example, one form ofthe passive transponder 150 may monitor the open/closed state of awindow or door via an intrusion sensor. An intrusion sensor 600 willtypically be a two-state device; however, the passive transponder 150may also support multi-state devices. The passive transponder 150 willtypically report its status and the status of an attached sensor 600 or620 periodically. This periodic status message serves as a “heartbeat”by which the base unit 200 can supervise each of the installedtransponders. The periodicity of the this status message may be set asone of the parameters sent by the master controller 251. Like theperiodic cycle discussed herein, the periodicity of the status messagesmay vary with the present state of the system.

There are two other times when the passive transponder 150 may reportits status: (i) in response to a status request message received from abase unit 200, or (ii) if the passive transponder 150 detects a changein the state of an attached sensor 600 or 620. If the passivetransponder 150 does detect a change in the state of an attached sensor,the passive transponder 150 may interrupt the communications that may beoccurring between a base unit 200 and a second passive transponder 150or the passive transponder 150 may wait for the next available listensignal from a base unit 200.

Because passive transponders 150 cannot initiate communications, theremay be times when there is a time lag between the time that the passivetransponder 150 detects a change in the state of an attached sensor ordevice and the time that the passive transponder 150 communicates with abase unit 200. The time lag will typically be based upon the operatingparameters of the security network 400, and may only be one or a fewseconds. However, the existence of any time lag creates the possibilitythat the state may change more than once during the time lag. Forexample, an intruder may open and close a window or door in just a fewseconds. Therefore, the passive transponder 150 may include a latch thatrecords any change in state of an attached sensor or device, howeverbrief the change of state may have been. The latch may be implementedusing logic gates, such as a flip flop, or in the state machine orprocessor of the passive transponder 150. The latch typically holds thestate change until at least the time that the passive transponder 150communicates the state change to a base unit 200. The passivetransponder 150 may either maintain the latched state change until thestate change has been communicated or may maintain the latched statechange until a base unit 200 sends a command that clears the latch.

One form of passive transponder 150 may typically be provided with anadhesive backing to enable easy attachment to the frame of an openingsuch as, for example, the frame of a window 702 or door 701. Passivetransponder 150 designs based upon modulated backscatter are widelyknown and the details of transponder 100 design are well understood bythose skilled in the art. The passive transponder 150 functions may beimplemented within a single chipset or may be implemented as separatecomponents in a circuit on a printed circuit substrate. The passivetransponder 150 receives and interprets commands from the base unit 200by typically including circuits for clock extraction 103 and datamodulation 104. The manner of implementing clock extraction 103 and datamodulation 104 will depend upon the type of modulation used for wirelesscommunications from the base unit 200 to the passive transponder 150.For example, if on-off keying is used, the data modulation 104 circuitcan be as simple as a diode. More complicated designs have been shown incircuits such as those disclosed in U.S. Pat. No. 6,384,648 and U.S.Pat. No. 6,549,064. The microcontroller 106 can send data and statusback to the base unit 200 by typically using a modulator 102 to controlthe impedance of the antenna 110. This modulator 102 may take the formof a single diode or FET or may be more complicated such as the patentexamples cited herein. The impedance control alternately causes theabsorption or reflection of the RF energy transmitted by the base unit200 thereby forming the response wireless communications. Themicrocontroller 106 may be implemented as a state machine designed intoa programmable logic array, or may be a processor controlled viafirmware. Each of these embodiments are designer choices that do notaffect the novelty of the invention.

Similarly, the energy store 108 has been shown internal to the passivetransponder 150; however, part or all of the energy store 108 may belocated off-board of the passive transponder 150 in order to providemore physical space for a larger energy store 108. If the energy store108 is a battery with sufficient capacity, it is possible that thepassive transponder 150 does not rely upon the power radiated from thebase unit 200 to periodically charge the energy store 108. If, however,the energy store 108 is a capacitor or low-capacity battery, then thepassive transponder 150 may include energy management circuits such asan overvoltage clamp 101 for protection and a rectifier 105 andregulator 107 to produce proper voltages for use by the charge pump 109in charging the energy store 108 and powering the microcontroller 106.

Low-cost chipsets and related components are available from a largenumber of manufacturers. In the present invention, the base unit 200 topassive transponder 150 radio link budget can be designed to operate atan approximate range of up to 30 meters. In a typical installation, eachopening will have a passive transponder 150 installed. The ratio ofpassive transponders 150 to each base unit 200 will typically be 3 to 8in an average residential home, although the technology of the presentinvention has no practical limit on this ratio. The choice of addressingrange is a designer's choice largely based on the desire to limit thetransmission of wasted bits. In order to increase the security of thetransmitted bits, the passive transponders 150 can include an encryptionalgorithm. The tradeoff is that this will increase the number oftransmitted bits in each message. The key to be used for encryption canbe exchanged during enrollment.

Passive transponders 150 are typically based upon a modulatedbackscatter design. Each passive transponder 150 in a room can absorbpower radiated from one or more base units 200 when the passivetransponder 150 is being addressed, as well as when other passivetransponders 150 are being addressed. In addition, the base units 200can radiate power for the purpose of providing energy for absorption bythe passive transponders 150 even when the base unit 200 is notinterrogating any passive transponders 150. Therefore, unlike most RFIDapplications in which the passive transponders or tags are mobile and inthe read zone of a conventional base unit briefly, the passivetransponders 150 of the present invention are fixed relative to the baseunits 200 and therefore always in the read zone of at least one baseunit 200. Therefore, the passive transponders 150 have extremely longperiods of time in which to absorb, integrate, and store transmittedenergy.

In a typical day-to-day operation, the base unit 200 is making periodictransmissions. The master controller 251 will typically sequence thetransmissions from the base units 200 so as to prevent interferencebetween the transmissions of any two base units 200. The mastercontroller 251 will also control the rates and transmission lengths,depending upon various states of the system. For example, if thesecurity network 400 is in a disarmed state during normal occupancyhours, the master controller 251 may use a lower rate of transmissionssince little or no monitoring may be required. When the security network400 is in an armed state, the rate of transmissions may be increased soas to increase the rate of wireless communications between the baseunits 200 and the various sensors. The increased rate of wirelesscommunications will reduce the latency from any attempted intrusion tothe detection of the attempted intrusion. The purpose of the varioustransmissions will generally fall into several categories including:power transfer without information content, direct addressing of aparticular passive transponder 150, addressing to a predetermined groupof passive transponders 150, general addressing to all passivetransponders 150 within the read range, and radiation for motiondetection.

A passive transponder 150 can typically only send a response wirelesscommunication in reply to a transmission from a base unit 200.Furthermore, the passive transponder 150 will typically only send aresponse wireless communication if the passive transponder 150 hasinformation that it desires to communicate. Therefore, if the base unit200 has made a globally addressed wireless communication to all passivetransponders 150 asking if any passive transponder 150 has a change instatus, a passive transponder 150 is not required to respond if in factit has no change in status to report. This communications architecturereduces the use of resources on multiple levels. On the other hand, ifan intrusion sensor 600 detects a probable intrusion attempt, it isdesirable to reduce the latency required to report the probableintrusion attempt. Therefore, the communications architecture alsoincludes a mechanism whereby a passive transponder 150 can cause aninterrupt of the otherwise periodic transmissions of any category inorder to request a time in which the passive transponder 150 can provideresponse wireless communications with the details of the probableintrusion attempt. The interrupt might be, for example, an extendedchange of state of the antenna (i.e., from terminate to shorted) or asequence of bits that otherwise does not occur in normal communicationsmessages (i.e., 01010101). An example sequence may be: (a) the base unit200 may be transmitting power without information content, (b) a firstpassive transponder 150 causes an interrupt, (c) the base unit 200detects the interrupt and sends globally addressed wirelesscommunications, and (d) the first passive transponder 150 sends itsresponse wireless communications. This example sequence may also operatesimilarly even if in step (a) the base unit 200 had been addressing asecond passive transponder 150; steps (b) through (d) may otherwiseremain the same.

If the passive transponder 150 does not contain an energy store 108 withsufficient capacity, energy to power the passive transponder 150 isderived from the buildup of electrostatic charge across the antennaelements 110 of the passive transponder 150. As the distance increasesbetween the base unit 200 and the passive transponder 150, the potentialvoltage that can develop across the antenna elements declines. Forexample, under 47 CFR 15.245 the base unit 200 can transmit up to 7.5 Wpower. At a distance of 10 m, this transmitted power generates a fieldof 1500 mV/m and at a distance of 30 m, the field declines to 500 mV/m.

The passive transponder 150 may therefore include a charge pump 109 inwhich to incrementally add the voltages developed across severalcapacitors together to produce higher voltages necessary to charge theon-board and/or off-board energy store 108 and/or power the variouscircuits contained within the passive transponder 150. Charge pumpcircuits for boosting voltage are well understood by those skilled inthe art. For example, U.S. Pat. No. 5,300,875 and U.S. Pat. No.6,275,681 contain descriptions of some examples.

One embodiment of the passive transponder 150 can contain a battery 111,such as a button battery (most familiar use is as a watch battery) or athin-film battery. Batteries of these shapes can be based upon variouslithium compounds that provide very long life. Therefore, rather thanrelying solely on a limited energy store 108 such as a capacitor, thepassive transponder 150 can be assured of always having sufficientenergy through a longer-life battery 111 component. In order to preservecharge in the battery 111, the microcontroller 106 of the passivetransponder 150 can place some of the circuits in the passivetransponder 150 into temporary sleep mode during periods of inactivity.The use of the battery 111 in the passive transponder 150 typically doesnot change the use of the passive modulated backscatter techniques asthe communications mechanism. Rather, the battery 111 is typically usedto enhance and assist in the powering of the various circuits in thepassive transponder 150.

One mechanism by which the passive transponder 150 replies to the baseunit 200 uses a modulation such as On-Off Keyed (OOK) amplitudemodulation. The OOK operates by receiving a carrier wave from the baseunit 200 at a center frequency selected by the base unit, or a mastercontroller 251 directing the base unit 200, and modulating marking(i.e., a “one”) and spacing (i.e., a “zero”) bits onto the carrier waveat shifted frequencies. The marking and spacing bits obviously use twodifferent shifted frequencies, and ideally the shifted frequencies areselected so that neither creates harmonics that can confuse theinterpretation of the marking and spacing bits. In this example, the OOKis not purely on and off, but rather two different frequency shiftsnominally interpreted in the same manner as a pure on-off might normallybe interpreted. The purpose is to actively send bits rather that usingthe absence of modulation to represent a bit. The use of OOK, and inparticular amplified OOK, makes the detection and interpretation of thereturn signal at the base unit 200 simpler than with some othermodulation schemes.

In addition to the charge pump 109 for recharging the battery 111, thepassive transponder 150 may contain circuits for monitoring the chargedstate of the battery 111. This state can range from fully charged todischarged in various discrete steps, and can be reported from thepassive transponder 150 to the base unit 200. For example, if thebattery 111 is sufficiently charged, the passive transponder 150 cansignal the base unit 200 using one or more bits in a communicationsmessage. Likewise, if the battery 111 is less than fully charged, thepassive transponder 150 can signal the base unit 200 using one or morebits in a wireless communications message. Using the receipt of thesemessages regarding the state of the battery 111, if present, in eachpassive transponder 150, the base unit 200 can take actions to continuewith the transmission of radiated power, increase the amount of powerradiated (obviously while remaining within prescribed FCC limits), oreven suspend the transmission of radiated power if no passivetransponder 150 requires power for battery charging. By suspendingunnecessary transmissions, the base unit 200 can conserve power andreduce the likelihood of causing unwanted interference.

One form of the transponder 100, excluding those designed to be carriedby a person or animal, is typically connected to at least one intrusionsensor 600. From a packaging standpoint, the present invention alsoincludes the ability to combine the intrusion sensors 600 and thetransponder 100 into a single package, although this is not arequirement of the invention.

The intrusion sensor 600 is typically used to detect the passage, orattempted passage, of an intruder through an opening in a building, suchas a window 702 or door 701. Thus, the intrusion sensor 600 is capableof being in at least two states, indicating the status of the window 702or door 701 such as “open” or “closed.” Intrusion sensors 600 can alsobe designed under this invention to report more that two states. Forexample, an intrusion sensor 600 may have 4 states, corresponding towindow 702 “closed,” window 702 “open 2 inches,” window 702 “openhalfway,” and window 702 “open fully.”

In a typical form, the intrusion sensor 600 may simply detect themovement of a portion of a window 702 or door 701 in order to determineits current state. This may be accomplished, for example, by the use ofone or more miniature magnets, which may be based upon rare earthmetals, on the movable portion of the window 702 or door 701, and theuse of one or more magnetically actuated miniature reed switches onvarious fixed portions of the window 702 or door 701 frame. Other formsare also possible. For example, pressure-sensitive contacts may be usedwhereby the movement of the window 702 or door 701 causes or relievesthe pressure on the contact, changing its state. The pressure-sensitivecontact may be mechanical or electro-mechanical such as a MEMS device.Alternately, various types of Hall effect sensors may also be used toconstruct a multi-state intrusion sensor 600.

In any of these cases, the input/output leads of the intrusion sensor600 are connected to, or incorporated into, the transponder 100 suchthat the state of the intrusion sensor 600 can be determined by and thentransmitted by the transponder 100 in a message to the base unit 200.

Because the transponder 100 is a powered device (with or without thebattery 111, the transponder 100 can receive and store power), and thebase unit 200 makes radiated power available to any device within itsread zone capable of receiving its power, other forms of intrusionsensor 600 design are also available. For example, the intrusion sensor600 can itself be a circuit capable of limited radiation reflection.Under normally closed circumstances, the close location of thisintrusion sensor 600 to the transponder 100 and the simultaneousreflection of RF energy can cause the generation of harmonics detectableby the base unit 200. When the intrusion sensor 600 is moved due to theopening of the window 702 or door 701, the gap between the intrusionsensor 600 and the transponder 100 will increase, thereby reducing orceasing the generation of harmonics. Alternately, the intrusion sensor600 can contain metal or magnetic components that act to tune theantenna 110 or frequency-generating components of the transponder 100through coupling between the antenna 110 and the metal components, orthe switching in/out of capacitors or inductors in the tuning circuit.When the intrusion sensor 600 is closely located next to the transponder100, one form of tuning is created and detected by the base unit 200.When the intrusion sensor 600 is moved due to the opening of the window702 or door 701, the gap between the intrusion sensor 600 and thetransponder 100 will increase, thereby creating a different form oftuning within the transponder 100 which can also be detected by the baseunit 200. The intrusion sensor 600 can also be an RF receiver, absorbingenergy from the base unit 200, and building an electrostatic charge upona capacitor using a charge pump, for example. The increasingelectrostatic charge will create a electric field that is small, butdetectable by a circuit in the closely located transponder 100. Again,when the intrusion sensor 600 is moved, the gap between the intrusionsensor 600 and the transponder 100 will increase, causing thetransponder 100 to no longer detect the electric field created by theintrusion sensor 600.

Another form of intrusion sensor 600 may be implemented with lightemitting diode (LED) generators and detectors. Two forms of LED-basedintrusion sensor 600 are available. In the first form, shown in FIG.25A, the LED generator 601 and detector 602 are incorporated into thefixed portion of the intrusion sensor 600 that is typically mounted onthe window 702 or door 701 frame. It is immaterial to the presentinvention whether a designer chooses to implement the LED generator 601and detector 602 as two separate components or as a single component.Then a reflective material, typically in the form of a tape 603 can beattached to the moving portion of the window 702 or door 701. If the LEDdetector 602 receives an expected reflection from the LED generator 601,then no alarm condition is present. If the LED detector 602 receives adifferent reflection (such as from the paint of the window rather thanthe installed reflector) or no reflection from the LED generator 601,then an intrusion is likely being attempted. The reflective tape 603 canhave an interference pattern 604 embedded into the material such thatthe movement of the window 702 or door 701 causes the interferencepattern 604 to move past the LED generator 601 and detector 602 that areincorporated into the fixed portion of the intrusion sensor 600. In thiscase, the movement itself signals that an intrusion is likely beingattempted without waiting further for the LED detector 602 to receive adifferent reflection or no reflection from the LED generator 601. Thespeed of movement is not critical, as the data encoded into theinterference pattern 604 and not the data rates are important. The useof such an interference pattern 604 can prevent easy defeat of theLED-based intrusion sensor 600 by the simple use of tin foil, forexample. A different interference pattern 604, incorporating a differentcode, can be used for each separate window 702 or door 701, whereby thecode is stored into the master controller 251 and associated with eachparticular window 702 or door 701. This further prevents defeat of theLED-based intrusion sensor 600 by the use of another piece of reflectivematerial containing any other interference pattern 604. This use of theLED-based intrusion sensor 600 is made particularly attractive by itsconnection with a transponder 100 containing a battery 111. The LEDgenerator 601 and detector 602 will, of course, consume energy in theirregular use. Since the battery 111 of the transponder 100 can berecharged as discussed elsewhere, this LED-based intrusion sensor 600receives the same benefit of long life without changing batteries.

A second form of LED-based intrusion sensor 600 is also available. Inthis form, the LED generator 601 and LED detector 602 are separated soas to provide a beam of light across an opening as shown in FIG. 25B.This beam of light will typically be invisible to the naked eye suchthat an intruder cannot easily see the presence of the beam of light.The LED detector 602 will typically be associated with the LED-basedintrusion sensor 600, and the LED generator 601 will typically belocated across the opening from the LED detector 602. In this form, thepurpose of the LED-based intrusion sensor 600 is not to detect themovement of the window 702 or door 701, but rather to detect a breakageof the beam caused by the passage of the intruder through the beam. Thisform is particularly attractive if a user would like to leave a window702 open for air, but still have the window 702 protected in case anintruder attempts to enter through the window 702. As before, it wouldbe preferred to modulate the beam generated by the LED generator 601 soas to prevent easy defeat of the LED detector 602 by simply shining aseparate light source into the LED detector 602. Each LED generator 601can be provided with a unique code to use for modulation of the lightbeam, whereby the code is stored into the master controller 251 andassociated with each particular window 702 or door 701. The LEDgenerator 601 can be powered by a replaceable battery or can be attachedto a transponder 100 containing a battery 111 so that the LED generator601 is powered by the battery 111 of the transponder 100, and thebattery 111 is recharged as discussed elsewhere. In this latter case,the purpose of the transponder 100 associated with the LED generator 601would not be to report intrusion, but rather only to act to absorb RFenergy provided by the base unit 200 and charge the battery 111.

In each of the cases, the transponder 100 is acting with a connected orassociated intrusion sensor 600 to provide an indication to the baseunit 200 that an intrusion has been detected. The indication can be inthe form of a message from the transponder 100 to the base unit 200, orin the form of a changed characteristic of the transmissions from thetransponder 100 such that the base unit 200 can detect the changes inthe characteristics of the transmission. It is impossible to know whichform of intrusion sensor 600 will become most popular with users of theinventive security network 400, and therefore the capability formultiple forms has been incorporated into the invention. Therefore, theinventive nature of the security network 400 and the embodimentsdisclosed herein are not limited to any single combination of intrusionsensor 600 technique and transponder 100.

In addition to the modulation scheme, the security network 400 mayinclude an RF access protocol that contains elements of various layersof the OSI communications reference model. This invention is notspecific to any chosen framing, networking, or related technique;however, there are a number of characteristics of the RF access protocolthat are advantageous to the invention.

It is preferred that base units 200 belonging to a common securitynetwork 400 are organized into a common frequency plan. Each base unit200 described herein is a wireless transmitter. For high power RFcommunications, base units 200 are governed by 47 CFR 15.247, which mayrequire each base unit 200 to periodically frequency hop. It ispreferred that the hopping sequences be organized in time and frequencysuch that no two base units 200 attempt to operate on the same frequencyat the same time. Even in an average home, a security network 400 of thepresent invention may typically include between 4 and 10 base units 200whose frequency management may be more complex than the few cordlessphones and/or a WiFi network that may also be collocated there. 47 CFR15.247 permits some forms of frequency coordination to minimizeinterference and collisions, and it is preferred that any base unit 200take advantage of those permissions.

Frequency coordination between the base units 200 contained in separatebut nearby security networks 400 may be required. Each security network400 will typically be operating its own network with its own frequencyplan, but in preferred implementations, the security networks 400 detectand coordinate in both time and frequency. This may be accomplished inthe following example manner. The base units 200 in any first securitynetwork 400 will typically have periods of time in which notransmissions are required. Rather than idle, these base units 200 mayperiodically scan the frequency band of interest to determine thepresence of other transmitters. Some of the other transmitters will becordless phones and WiFi wireless access points. The scanning base units200 can note the presence and frequency location of these other devices,especially the WiFi devices that typically maintain fixed frequencies.If the scanning base units 200 note that the same devices continue toconsistently occupy the same frequency locations, the first securitynetwork 400 may opt to avoid those frequency locations to avoidinterference. If the scanning base units 200 discover transmitters thatare base units 200 from a second security network 400, the firstsecurity network 400 can frequency coordinate with the second securitynetwork 400. Then, rather than avoiding certain frequency locations toavoid interference, the two systems can share common frequencies as longas any specific frequency location is not simultaneously used by the twosystems.

In order to improve coordination between base units 200, whether part ofthe same security network 400 or separate but nearby security networks400, it may be advantageous for the base units 200 to synchronize theirinternal timing with each other. Since any chosen RF access protocolwill likely organize its transmissions into bursts, operation of thesystems will typically be improved if the timing between base units 200is synchronized so that bursts are both transmitted and received atexpected times. One method by which this may be accomplished is byestablishing one base unit 200 as a timing master; then each other baseunit 200 may derive its own internal timing by synchronizing with thetiming master. This synchronization may be accomplished by the base unit200 listening to certain bursts transmitted from the timing master andthen adjusting the base unit's timing accordingly. This may beaccomplished, for example, by monitoring the framing boundaries orsynchronization words of transmitted frames. The base unit 200designated as timing master may or may not be the same as the devicecontaining the present master controller 251.

If sufficient timing and frequency coordination between separate butnearby security networks 400 has been established, these separatesystems may also communicate with each other by establishing periodicfrequencies and times at which messages are passed between the systems.This ability to pass messages between adjacent systems enables variousforms of neighborhood networking to take place as described herein.

The RF access protocol may establish periods of time for communicationsbetween base units 200 and periods of time for communications betweenbase units 200 and transponders 100. Base units 200 will typicallytransmit a wireless signal to the transponders at periodic intervals.During the time of these transmitted wireless signals, the passivetransponders 150 may elect to backscatter modulate the transmittedwireless signals if any of the passive transponders 150 have informationto communicate. The periodic intervals may change depending upon thestate of the security network 400. For example, when the securitynetwork 400 is in an armed state, the base units 200 may transmit awireless signal to passive transponders 150 every two seconds. Thismeans that any state change at an intrusion sensor may be communicatedto the master controller 251 within two seconds. However, when thesecurity network 400 is in a disarmed state, the base units 200 may slowdown their rate of transmitting wireless signals to the passivetransponders 150 to every 30 seconds, for example, in to conserve power.The actual times may vary in practice, of course.

The rate of scanning is one of several parameters that the base units200 may transmit to the transponders 100. These parameters as a groupmay be used by the various transponders 100 to determine theirrespective operation. The rate of scanning may be used by thetransponders 100 to determine how often the transponders 100 shouldattempt to receive communications from the base units 200 as well aswhen and how often a transponder 100 has an opportunity to respond towireless communications from the base unit 200. Transponders 100 mayplace some or all their circuits to sleep during intervals of time whenthe transponder 100 is not expecting to receive communications nor hasany data to send. As the rate of scanning changes, the length of sleepintervals may also change.

The RF access protocol may or may not include encryption andauthentication as part of its message structure. Radio waves canpropagate over significant distances, and the communications betweenbase units 200 and with transponders 100 can be intercepted by atechnically knowledgeable intruder. If the designer of a securitynetwork 400 under the present invention is concerned about theinterception of communications, the messages may be encrypted. Duringthe manufacture and/or configuration of the security network 400, keysmay be provided to the various active and passive transponders. Once thedevices have the keys, and the keys are known by the controllerfunctions, the keys may be used for authentication and/or encryption.

Authentication is a process that typically involves the determination ofa challenge message using a predetermined method and typically involvingat least one key. The challenge message is then sent from a first deviceto a second device. The second device typically then determines aresponse message using a predetermined method and typically involvingboth the challenge message and at least one key. The premise is thatonly a valid second device knows both the method and the key required toproperly respond to the challenge from the first device. There are manyauthentication processes known by those skilled in the art, almost anyof which can be applied to the present security network 400.

Encryption is a related process that typically involves both a first keyand a predetermined method for using the first key to encode or encrypta message. The encrypted message is then sent from a first device to asecond device. The second device can typically decrypt or decode themessage using a predetermined method and typically involving a secondkey known to the second device. The first key and the second key may bethe same, or may have some other predetermined relationship that allowsone key to decrypt messages from another key. It may be advantageous forthe keys to be different so that if one key is compromised, it ispossible to maintain the integrity of the remainder of the system.

The present security network 400 may be controlled by the user via akeypad 265, which may be implemented in a handheld unit 260 or tabletopunit 261 for example. However, the present security network 400 alsosupports a novel method for configuration primarily using voicerecognition. This novel method is not necessarily specific to a securitynetwork 400 employing communication methods as disclosed herein, but mayalso be applied to other types of security systems such as those inexistence.

Most security networks 400, especially those that will be monitored,include a modem 310. In the security network 400 of the presentinvention, the modem 310 is contained in a gateway 300. Then, after allof the components of the security network 400 are installed in thebuilding and the modem is connected to the telephone line 431 thefollowing process is then used to configure the security network 400:

-   -   1. The user 712 (or owner or operator) uses a base unit 200 with        an acoustic transducer 210 or even a telephone 455 connected to        the same telephone line 431 as the modem 310 to call a remote        processor 461, which may typically be located at an emergency        services center 460. The user interaction is depicted by arrow A        in FIG. 19.    -   2. The remote processor 461 runs a configuration program that        includes voice recognition and voice response. Data may be        exchanged between the configuration program on the remote        processor 461 and the modem 310 using DTMF, data over voice,        data under voice, or similar modulation techniques that enable        voice and data to share the same telephone line 431 (data        exchange is depicted by arrow B in FIG. 19). Furthermore, data        may be exchanged between base units 200 (depicted by arrow C in        FIG. 19) and between base units 200 and transponders 100        (depicted by arrows D in FIG. 19) during the configuration        process.    -   3. When the user has finished the configuration program, the        user may hang up the telephone 455 or terminate the voice        conversation on the base unit 200 with acoustic transducer 210.        However, the modem 310 attached to the same telephone line 431        may hold the telephone line 431 active.    -   4. The remote processor 461 and the modem 310 may engage in a        data exchange in which software, parameters, and other        configuration data may be downloaded.    -   5. The modem 310 releases the telephone line 431 when the        download is complete.

There are many advantages to this configuration process:

-   -   The security network 400 is not burdened with the program code        and data required to run a configuration program that includes        voice recognition and voice response. The amount of memory        required to support this program code and data can be        substantial, and it is generally only required at initial setup.    -   The remote processor 461 can have more substantial processing        power, and therefore execute more complex algorithms for voice        recognition than a low-cost microprocessor that might typically        be used in a security network 400. More complex algorithms will        generally perform with better voice recognition accuracy.        Additionally, the remote processor 461 can include the data to        support multiple languages so that the user can interact in the        language most comfortable to the user.    -   During the data exchange (arrow B), updated software can be        downloaded into the security network 400. By calling the remote        processor 461 prior to using the security network 400, the user        712 is ensured of always receiving the latest version of        software, even if the security network 400 was manufactured many        months before the actual purchase.    -   During the configuration program, the user 712 can be offered        additional software-based features for purchase. These features        may not be part of the basic security network 400. If the user        chooses to purchase the additional software-based features, this        new software can be downloaded to the security network 400        during the data exchange (arrow B).    -   The remote processor 461 maintains a copy of the configuration        for the security network 400 in the event of catastrophic loss        of data in the security network 400.    -   The user 712 can create his or her own spoken labels for        different zones, base units 200, transponders 100, or other        components of the security network 400. In the case of the        inventive security network 400, which can support voice        response, these labels can be downloaded to the inventive        security network 400 during the data exchange. Then, if the        security network 400 needs to identify a specific zone, base        unit 200, transponder 100, or other component, the inventive        security network 400 can play back the user's 712 own spoken        label via an acoustic transducer 210 in a base unit 200.

It is preferable that the remote processor 461 and the security network400 engage in an authentication and/or encryption process to protect theconfiguration data exchanged between the remote processor and thesecurity network 400. While it is unlikely that an intruder would bemonitoring the telephone line 431 at the exact moment that the user 712(or owner or operator) is configuring the security network 400 for thefirst time, it is possible that a technically knowledgeable intrudermight attempt later to compromise the security network 400 by accessingthe telephone line 431 exterior to the building. For example, oneattempt at compromise might be to connect a telephone to the telephoneline 431 exterior to the building, call the remote processor 461, andattempt to reconfigure the security network 400.

One way in which the security network 400 and its configuration can beprotected is by storing a user identity, a password, and a key at theremote processor 461. When a user calls the remote processor 461 for thefirst time, the security network 400 attached via the modem 310 to thetelephone line 431 will be in a starting state with no configuration.There will also be no user record on the remote processor 461. The user712 will be required to initiate a user record, beginning with a useridentity and password. The user identity may be the home telephonenumber, or any other convenient identity. The remote processor 461 maydetect that the security network 400 is in a starting state, and canassign a first key to the user record and a second key to the securitynetwork 400. The first and second keys may be the same key or may beanother predetermined relationship that enables the remote processor 461and the security network 400 to engage in an authentication processand/or an encryption process. Different types of authentication andencryption processes are known to those skilled in the art, and anyacceptable process may be implemented. An example of each process hasbeen provided herein. Instead of the remote processor 461 assigning akey to the security network 400, it is also acceptable for the securitynetwork 400 to contain a predetermined key that is then provided to theremote processor 461 by the user or the security network 400. It ispreferable that whichever method is used for the exchange of keys amongthe user, security network 400, and remote processor 461, the keys beprovided only once over the telephone line. Keys are most useful whentheir values are not discovered by someone that might attempt anintrusion, and by providing the keys only once the chances of discoveryby monitoring the telephone line 431 are minimized.

Once the remote processor 461 contains a first key associated with theuser record, and the security network 400 contains a second key, anyattempt to change the configuration of the security network 400 willrequire the use of the keys. An intruder attempting to compromise thesecurity network 400 by accessing the telephone line 431 exterior to thebuilding would be required to know the user identity and password inorder to access the user record in the remote processor 461, and thefirst key can only be used by accessing the user record.

The inventive security network 400 can assist the user during theconfiguration program by providing certain data (arrows B, C, D) to theremote processor 461 during the call while the user is interacting(arrow A) with the configuration program. The certain data may includethe number of base units 200, the transponders 100 within detectionrange of each base unit 200, and the number of gateways 300 and otherdevices within the security network 400. This data may be sent to theremote processor 461 while the user is interacting with theconfiguration program (arrow A) either by modulating the data outside ofthe normal audio bandwidth of a telephone call or using a modulationlike DTMF tones to send the data within the audio bandwidth. In asimilar manner, the remote processor 461 may send certain commands tothe security network 400. For example, it may be advantageous for theremote processor 461 to cause certain base units 200 to emit a shorttone or spoken phrase to identify itself. Then the user 712 may providean audio label to the base unit 200 that had emitted the short tone.

One advantageous interface mechanism available for use with the securitynetwork 400 is voice recognition and voice response. When a base unit200 is manufactured with an acoustic transducer 210, the base unit 200can also include software-based functionality in the program code 251 tointerpret spoken words as commands to the security network 400.Similarly, the security network 400 can respond to spoken word commandswith spoken word responses or tones. Software to perform voicerecognition and voice response is widely available and known to thoseskilled in the art, though most existing software must be modified tosupport the relatively noisy environment of the typical home. U.S. Pat.No. 6,574,596, issued to Bi et al., provides one example description ofvoice recognition, as do several well-known textbooks. With the voicerecognition and voice response as the primary interface mechanism, it ispossible to implement a version of the inventive security network 400with no keypad 265. The base units 200 with acoustic transducers 210 canbe used by authorized users to perform various functions, including theday-to-day functions such as arming and disarming the system. Oneattractive advantage of incorporating voice recognition and voiceresponse into the security network 400 via the acoustic transducer 210in the base unit 200 is that the security network 400 can be armed ordisarmed from any room in the house in which a base unit 200 isinstalled. The voice commands received at a single base unit 200 can becommunicated to the controller functions 250 of all other devices in thesecurity network 400.

In addition to its support of multiple modulation schemes, the base unit200 is available in an embodiment with multiple antennas 206 thatenables the base unit 200 to subdivide the space into which the baseunit 200 transmits and/or receives. It is well known in antenna designthat it is desirable to control the radiation pattern of antennas toboth minimize the reception of noise and maximize the reception ofdesired signals. An antenna that radiates equally in all directions istermed isotropic. An antenna that limits its radiation into a largedonut shape can achieve a gain of 2 dBi. By limiting the radiation tothe half of a sphere above a ground place, an antenna can achieve a gaina 3 dBi. By combining the two previous concepts, the gain can be furtherincreased. By expanding upon these simple concepts to create antennasthat further limit radiation patterns, various directional gains can beachieved. The base unit 200 circuit design permits the construction ofembodiments with more than one antenna, whereby the transceiver circuitscan be switched from one antenna to another. In one embodiment, the baseunit 200 will typically be plugged into an outlet 720. Therefore, thenecessary coverage zone of the base unit 200 is logically bounded by theplanes created by the floor below the reader and the wall behind thereader. Therefore, relative to an isotropic antenna, the read zone ofthe base unit 200 should normally be required to cover the spacecontained within only one-quarter of a sphere. Therefore, a singleantenna configured with the base unit 200 should typically be designedat a gain of approximately 6 dBi.

However, it may be desirable to further subdivide this space intomultiple subspaces, for example a “left” and a “right” space, withantenna lobes that overlap in the middle. Each antenna lobe may be thenable to increase its design gain to approximately 9 dBi or more. Sincethe base units 200 and transponders 100 are fixed, the base unit 200 can“learn” in this example “left”/“right” configuration which transponders100 have a higher received signal strength in each of the “left” and“right” antennas 206. The simplest method by which this can be achievedis with two separate antennas 206, with the transceiver circuits of thebase unit 200 switching between the antennas 206 as appropriate for eachtransponder 100. This enables the base unit 200 to increase its receiversensitivity to the reflected signal returning from each transponder 100while improving its rejection to interference originating from aparticular direction. This example of two antennas 206 can be expandedto three or four antennas 206. Each subdivision of the covered space canallow a designer to design an increase in the gain of the antenna 206 ina particular direction. Because the physical packaging of the base unit200 has physical depth proportionally similar to its width, athree-antenna 206 pattern is a logical configuration in which to offerthis product, where one antenna 206 looks forward, one looks left, andthe other looks right. An alternate configuration, which is equallylogical, can employ four antennas 206: one antenna 206 looks forward,the second looks left, the third looks right, and the fourth looks up.These example configurations are demonstrated in FIGS. 22A and 22B. Toaid in visual understanding, the antennas shown in FIGS. 22A and 22Bappear to be microstrip or patch antennas, however the invention is notintended to be limited to those antenna forms. Other forms of antennassuch as dipole, bent dipole, helical, etc. that are well known in theart can also be used without subtracting from the invention.

There are multiple manufacturing techniques available whereby theantennas can be easily printed onto circuit boards or the housing of thebase unit 200. For example, the reader is directed to Compact andBroadband Microstrip Antennas, by Kin-Lu Wong, published by Wiley(2002), as one source for a description of the design and performance ofmicrostrip antennas. The present specification does not recommend thechoice of any one specific antenna design, because so much relies on thedesigner's preference and resultant manufacturing costs. However, whenconsidering the choice for antenna design for both the base unit 200 andthe transponder 100, the following should be taken into consideration.Backscatter modulation relies in part upon the Friis transmissionequation and the radar range equation. The power P_(r) that thereceiving base unit 200 can be expected to receive back from thetransponder 100 can be estimated from the power P_(t) transmitted fromthe transmitting base unit, the gain G_(t) of the transmitting base unit200 antenna, gain G_(r) of the receiving base unit 200 antenna, thewavelength λ of the carrier frequency, the radar cross section σ of thetransponder 100 antenna, and the distances R₁ from the transmitting baseunit 200 to the transponder 100 and R₂ from the transponder 100 to thereceiving base unit 200. (Since more than one base unit 200 can receivewireless communications from the transponder 100, the general case isconsidered here.) The radar range equation is then:P _(r) =P _(t) ·σ·[G _(t) ·G _(r)/4π]·[λ/4πR ₁ R ₂]²Therefore, the designer should consider antenna choices for the baseunits 200 and transponders 100 that maximize, in particular, G_(r) andσ. The combination of P_(t) and G_(t) cannot result in a field strengththat exceeds the prescribed FCC rules. The foregoing discussion ofmicrostrip antennas does not preclude the designer from consideringother antenna designs. For example, dipoles, folded dipoles, and logperiodic antennas may also be considered. Various patents such as U.S.Pat. No. 6,147,606, U.S. Pat. No. 6,366,260, U.S. Pat. No. 6,388,628,and U.S. Pat. No. 6,400,274, among others, show examples of otherantennas that can be considered. Unlike other applications for RFID, thesecurity network 400 of the present invention uses RFID principles in aprimarily static relationship. Furthermore, the relationship between thebase unit 200 antennas and transponder 100 antennas will typically beorthogonal since most buildings and homes have a square or rectangularlayout with largely flat walls. This prior knowledge of the generallystatic orthogonal layout should present an advantage in the design ofantennas for this RFID application versus all other RFID applications.

In addition to performing the functions described herein within a singlebuilding or home, the security network 400 in one building can alsooperate in concert with an inventive security network 400 installed inone or more other buildings through a networking capability. There aretwo levels of networking supported by the security network 400: localand server-based. Local networking operates using high power RFcommunications between security networks 400 installed in two differentbuildings. Because of the power levels supported during high power RFcommunications, the distance between the security networks 400 in thetwo buildings can be a mile or greater, depending upon terrain. Each ofthe security networks 400 remains under the control of their respectivemaster controllers 251, and the controller function 250, including boththe program code and configuration data, of each device remainsdedicated to its own security network 400. However, an authorized userof one security network 400 and an authorized user of a second securitynetwork 400 can configure their respective systems to permitcommunications between the two security networks 400, thereby creating anetwork between the two systems. This network can exist between morethan just two systems; for example, an entire neighborhood of homes,each with an inventive security network 400, can permit their respectivesecurity networks 400 to network with other security networks 400 in theneighborhood.

When two or more security networks 400 are networked using high power RFcommunications, various capabilities of each security network 400 can beshared. For example, a first security network 400 in a first home 740can access a gateway 300 associated with a second security network 400in a second home 741 (as shown in FIG. 17). This may be advantageous if,for example, an intruder were to cut the phone line associated with thefirst home 740, thereby rendering useless a gateway 300 containing amodem 310 installed in the first security network 400. It is unlikelythat an intruder would know to cut the phone lines associated withmultiple homes. In another example, if a child wearing a transponder 100associated with the first security network 400 is present in the secondhome, the second security network 400 can communicate with thetransponder 100 on the child and provide the received transponder 100data to the first security network 400, thereby enabling a parent tolocate a child at either the first home or the second home. In yetanother example, if the first security network 400 in the first home 740causes an alert, the first security network 400 can request the secondsecurity network 400 to also cause an alert thereby notifying theneighbors at the second home 741 of the alert and enabling them toinvestigate the cause of the alert at the first home 740. This may beuseful if, for example, the occupants are away on travel. In yet anotherexample, the base units 200 in a second security network 400 in a secondhome 741 may be within communications range of the transponders 100 in afirst security network 400 in a first home 740. The base units 200 inthe second security network 400 may forward any received communicationsto the controller function 250 in the first security network 400,thereby providing another form of spatial antenna diversity. This may beparticularly useful for any transponders 100 located outside of the homewhere the first security network 400 is installed.

When two security networks 400 are beyond the range of communicationsvia high power RF communications, the security networks 400 may stillform a network through their respective gateways 300. The securitynetworks 400 may either network through direct connection between theirrespective gateways 300 or may network through an intermediate server461. The use of an intermediate server 461 can enable the first securitynetwork 400 and the second security network 400 to have different typesof communications modules (i.e., modem, Ethernet, WiFi, USB, wireless,etc.) installed in the gateway 300 of each respective security network400. Since a commercial emergency response agency 460 will likelyalready have servers 461 equipped to support the various types ofcommunications modules installed in various gateways 300, the provisionof an intermediate server for networking security networks 400 maypresent an expanded business opportunity.

Networking through intermediate servers 461 expands the applications andusefulness of the inventive security network 400. For example, there maybe a caregiver that would like to monitor an elderly parent living alonein another city. Using the networking feature, the caregiver can monitorthe armed/disarmed status of the security network 400 in the home of theelderly parent, use two-way audio and/or the camera 213 of the securitynetwork 400 to check on the elderly parent, and monitor any transponder100 worn by the elderly parent. This may be equally useful for parentsto monitor a student living away at college or other similar familysituations.

In either form of networking, the security network 400 can provide anauthentication mechanism to ensure that networking is not inadvertentlyenabled with another unintended security network 400. The authenticationmechanism may consist of the mutual entering of an agreed security codein each of the two security networks 400 which are to network. In theircommunications with each other, the two security networks 400 may sendand verify that the security codes properly match before permittingvarious operations between the two systems. Other authenticationmechanisms may also be used, such as the shared use of a designatedmaster key. In this example, rather that requiring the mutual enteringof an agreed security code, each of the security networks 400 which areto network can be required to first read the same designated master key.

Other embodiments of transponders 100 may exist under the presentinvention. Two example forms of passive infrared sensors 570 can becreated by combining a passive infrared sensor 570 with the circuits ofthe transponder 100. As shown in FIG. 14A, in one embodiment the passiveinfrared sensor 570 with its power supply 207 is integrated into thepackaging of a light switch 730. Within this same packaging, atransponder 100 is also integrated. The passive infrared sensor 570operates as before, sensing the presence of a warm body 710. The outputof the passive infrared sensor 570 circuits is connected to thetransponder 100 whereby the transponder 100 can relay the status of thepassive infrared sensor 570 (i.e., presence or no presence of a warmbody 710 detected) to the base unit 200, and then to the mastercontroller 251. At the time of system installation, the mastercontroller 251 is configured by the user thereby identifying the roomsin which the base units 200 are located and the rooms in which thepassive infrared sensors 570 are located. If desired, the mastercontroller 251 can then associate each passive infrared sensor 570 withone or more base units 200 containing microwave Doppler algorithms. Themaster controller 251 can then require the simultaneous ornear-simultaneous detection of motion and a warm body, such as a person710, before interpreting the indications as a probable person in theroom.

It is not a requirement that the passive infrared sensor 570 be packagedinto a light switch 730 housing. As shown in FIG. 14B, in anotherembodiment the passive infrared sensor 570 is implemented into astand-alone packaging. In this embodiment, both the passive infraredsensor 570 and the transponder 100 are battery 208 powered so that thissensor/transponder 100 combination can be located anywhere within aroom. So, for example, this embodiment allows the mounting of thisstand-alone packaging on the ceiling, for a look down on the coveredroom, or the mounting of this stand-alone packaging high on a wall.

A single security network 400 is comprised of various embodiments ofbase units 200 and transponders 100 that the end-user desires toassociate with each other. There may be multiple security networks 400installed in close proximity to each other, such as within a singlebuilding, group of buildings, or neighborhood. It is therefore importantthat the proper base units 200 and transponders 100 become enrolled withthe proper security network 400, and not mistakenly enrolled with thewrong security network 400. Base units 200 that are enrolled with themaster controller 251 of a security network 400 may be controlled bythat master controller 251. Similarly, transponders 100 enrolled withthe master controller 251 of a security network 400 will be monitored bythat security network 400. For the purposes of describing the variousprocesses and states during configuration and enrollment, theterminology of the following paragraph shall be used.

The security network 400 within an end-user's residence (or similarsingular premise, whether residential, commercial, or otherwise) shallbe termed the home security network 400. This example residence may beresidence 740 as shown in FIG. 17. Other security networks 400 within RFcommunications range of the home security network 400, but whosecomponents are not owned by the end-user or intended to be enrolled withthe home security network 400, are termed neighbor security networks400. This neighbor security network 400 may be located in exampleresidence 741. There may, of course, be multiple neighbor securitynetworks 400 within RF communications range of the home security network400. Individual components of a security network 400, such as thevarious embodiments of base units 200 and transponders 100, may be inone of two states with respect to the various processes of configurationand enrollment: enrolled or not enrolled. Each security network 400 willtypically have a separate network identifier, or network ID, that isunique from the network ID of all other security networks 400 within RFcommunications range of the security network 400. Individual componentsof a home security network 400, such as the various embodiments of baseunits 200 and transponders 100, will typically each have a serial numberthat is unique and different from the serial numbers of other componentsin use by any neighbor security network 400 within RF communicationsrange of the home security network 400. The serial number for a specificcomponent may or may not be assigned at the time of manufacture. If theserial number is not assigned at the time of manufacture, the homesecurity network 400 for a component may assign a serial number to thatcomponent. This may typically happen, for example, at the time ofenrollment. It is particularly advantageous if the serial numbersassigned to components were encoded in a manner that identified thattype of component. For example, a different numeric or alphanumericrange may be assigned to each type of component.

When a component is first purchased and brought within RF communicationsrange of a home security network 400, it will typically be in a state of“not enrolled.” The component will remain in a state of “not enrolled”until the home security network 400 takes action to enroll thatcomponent. If the component, such as a base unit 200 or a transponder100, contains a power source, such as a battery, or becomes powered,such as by plugging the component into an outlet, connecting a battery,or receiving transmitted RF power, the component may begin communicatingaccording to a predetermined algorithm. The home security network 400may receive communications from the component, even though in the stateof “not enrolled,” but may not manage or monitor the component. The homesecurity network 400 may notify the end-user that a component has beendetected, but that the component is not enrolled. The end-user may thendecide whether to enable the home security network 400 to enroll thecomponent with the home security network 400.

Some components may be capable of storing their enrolled/not enrolledstate within the component itself. Other components may not be capableof storing their enrolled/not enrolled state, and therefore the homesecurity network 400 must store the enrolled/not enrolled state of thecomponent. Typically, base units 200 will contain the necessary storagemechanism to store their enrolled/not enrolled state. Similarly, sometransponders 100 will also contain the necessary storage mechanism tostore their enrolled/not enrolled state.

When a home security network 400 receives communications from acomponent, the serial number of the component may be entered into atable, which table will typically be located in a memory 211 of themaster controller 251 of the home security network 400. If the componenthas a state of “enrolled,” then the home security network 400 willtypically not be required to take any further action. If the componenthas a state of “not enrolled,” then the home security network 400 mayexchange communications with neighbor security networks 400 to determinewhether any of the neighbor security networks 400 have receivedcommunications from the same component, but have entered the componentinto their respective tables with a state of “enrolled.” If so, then thehome security network 400 may enter the component into a table, butrecord the state of the component as enrolled with a neighbor securitynetwork 400. In this manner and over time, the home security network 400may continue to add components to a table, in each case entering eachcomponent as enrolled with the home security network 400, enrolled witha neighbor security network 400, or not enrolled. When the state of acomponent has been determined to be enrolled in a neighbor securitynetwork 400, the home security network 400 may forward anycommunications received from the component to the neighbor securitynetwork 400. In this manner, the home security network 400 may provideantenna and communications diversity for the component in ensuring thatthe component's communications reach the neighbor security network 400.

When the home security network 400 has received communications from acomponent and the component is in a state of “not enrolled” in theeither the home security network 400 or in any neighbor network, theend-user may decide to enroll the component in the home security network400. A designer may choose any of various mechanisms, typically througha user interface, in which to enable the home security network 400 tonotify the end-user of the “not enrolled” component, and then enable theend-user to permit the component to become enrolled in the home securitynetwork 400. During the process of enrollment, the end-user may bepermitted to associate specific components with each other or withlocations on the end-user's premises. For example, a component installedin the living room of the end-user's house may be labeled within thehome security network 400 as a living room window transponder 100.

For components that are capable of storing their enrolled or notenrolled state, the components may use different serial numbers in theircommunications when enrolled and when not enrolled. For example, whenits state is “not enrolled” a component may use a first serial number ofa first predetermined length. When the same component is in an enrolledstate, the same component may use a second serial number of a secondpredetermined length. The second predetermined length may be shorterthan the first predetermined length, and the second serial number may bean abbreviated form of the first serial number. This may enable shortertransmissions when the component is in an enrolled state. On the otherhand, the second predetermined length may be longer than the firstpredetermined length. For example, when a component is an enrolled statethe second serial number may be a combination of the first serial numberand the network ID of the home security network 400. The presence of thenetwork ID of the home security network 400 in the second serial numbermay be used in the routing of communications. For example, a neighborsecurity network 400 may receive communications from a component and usethe second serial number to identify that the component is enrolled withthe home security network 400 and may forward the communications to thehome security network 400.

In addition to allowing an end-user to permit a component to be enrolledin the home security network 400, the home security network 400 may alsopermit the end-user to assign a label to the component. One way in whicha label may be assigned to a component is by enabling the end-user torecord a verbal label for the component. This verbal label may be storedin the master controller 251 or any other controller function 250. Ifany base units 200 in the home security network 400 have an audiotransducer, then the audio labels may be played back to the end-user atan appropriate time, such as when the security network 400 signals analarm condition. If the transponder 100 has not been manufactured with apredetermined serial number, the base unit 200 can generate, using apredetermined algorithm, a serial number and, if desired, any otherinformation necessary to engage in encrypted communications and downloadthese values to the transponder 100. If the transponder 100 requires apower level higher than normally available to enable the permanentprogramming of these downloaded values into its microcontroller 106 ormemory (in whatever form such as fuses, flash memory, EEPROM, orsimilar), a base unit 200 can increase its transmitted RF powersubsequent to the downloading. No values need be transmitted during theperiod of higher transmitted RF power, and therefore there is no risk ofthe values being intercepted outside of the close proximity of the baseunit 200 and transponder 100. After this particular exchange, thetransponder 100 is enrolled, and the master controller 251 may providesome form of feedback, such as audible or visual, to the user indicatingthat the transponder 100 has been enrolled.

The base unit 200 is not limited to reading just the transponders 100installed in the openings of the building. The base unit 200 can alsoread transponders 100 that may be carried by individuals 710 or animals711, or placed on objects of high value. By placing a transponder 100 onan animal 711, for example, the controller function 250 can optionallyignore indications received from the motion sensors if the animal 711 isin the room where the motion was detected. By placing a transponder 100on a child, the controller function 250 can use a gateway 300 to send amessage to a parent at work when the child has arrived home or, equallyimportant, if the child was home and then leaves the home. Thetransponder 100 can also include a button than can be used, for example,by an elderly or invalid person to call for help in the event of amedical emergency or other panic condition. When used with a button, thetransponder 100 is capable of reporting two states: one state where thetransponder 100 simply registers its presence, and the second state inwhich the transponder 100 communicates the “button pressed” state. Itcan be a choice of the system user of how to interpret the pressing ofthe button, such as causing an alert, sending a message to a relative,or calling for medical help. Because the base units 200 will typicallybe distributed throughout a house, this form of panic button can providea more reliable radio link than conventional systems with only a singlecentralized receiver.

Embodiments of base units 200 and transponders 100 may also be made intoforms compatible with various vehicles, water craft, lawn and farmequipment, and similar types of valuable property. For example, oneembodiment of a base unit 200 or transponder 100 may be made in anexample physical embodiment of a cigarette lighter adaptor 436, as shownin FIG. 26. Given the wide use of cigarette lighter adaptors forcharging cell phones and powering other equipment, there are someexample vehicles that have cigarette lighters that are constantlypowered, even when the vehicle has been turned off. A base unit 200 ortransponder 100 in the form of a cigarette lighter adaptor 436 providesan easily installed way to monitor the vehicle against the risk oftheft. Of course, other forms of base units 200 and transponders 100 mayalso be designed that attach in other areas of vehicles, water craft,lawn and farm equipment, and similar types of property. Some forms maybe permanently wired. Even if a cigarette lighter has switched power, abase unit 200 or transponder 100 in the form of a cigarette lighteradaptor 436 may still be used if the base unit 200 or transponder 100contains a battery. The battery may be periodically recharged when thevehicle is running. Since base units 200 are capable of high power RFcommunications, their RF propagation range can be much farther than atransponder 100.

One advantageous security network 400 that may be formed may include onebase unit 200 or transponder 100 located in a vehicle and a second baseunit 200 that is handheld (i.e., example embodiment 260). Thus, thesecurity network 400 is not permanently affixed to a building, butrather travels with the user. When a user drives to a mall, for example,a first base unit 200 may remain in the vehicle and a second base unit200 may be carried by the user, and the two base units 200 may continuetheir communications. If the first base unit 200 detects an attemptedintrusion, the first base unit 200 may send a communications message tothe second base unit, and the second base unit 200 may cause an alert tonotify the user. In addition, the first base unit 200 may include acamera 213, as described elsewhere in this specification, and the secondbase unit 200 may include a display 266 on which pictures may be viewed.The first base unit 200 may periodically record and/or send pictures tothe second base unit, and, in particular, the first base unit 200 mayrecord and/or send pictures during the time in which the first base unit200 is detecting an attempted intrusion. This may enable the user toobtain a picture-based record of the activities involving the vehicleduring the time when the vehicle was parked and the user was away fromthe vehicle.

A user may configure a security network 400 in the home to include abase unit 200 or transponder 100 in a vehicle when the vehicle islocated within RF propagation range of a home security network 400 orneighbor security network 400. Similarly, a user may configure asecurity network 400 in the home to ignore a base unit 200 ortransponder 100 in the vehicle when the vehicle has traveled outside ofRF propagation range of a home security network 400 or neighbor securitynetwork 400. This configuration enables the base unit 200 or transponder100 in the vehicle to join the home security network 400 and thereforethe user can monitor the status of the vehicle when the vehicle isparked in or near to their home. The same base unit 200 or transponder100 in the vehicle can then be used as described above to monitor thevehicle when the user has driven the vehicle to another location such asan example mall. This form of security network 400 differs significantlyfrom present forms of vehicle security systems that only make noiselocally at the vehicle when the vehicle is disturbed.

The inventive security network 400 provides a number of mechanisms forusers and operators to interface with the security network 400. Thesecurity network 400 may include a base unit 200 with a keypad 265similar to a cordless phone handset 260 or cordless phone base 261 asshown in FIG. 4 since it is a convenient mechanism by which authorizedpersons can arm or disarm the system and view the status of variouszones. There are a number of keypad options that can be made availablefor the security network 400, derived from permutations of the followingpossibilities: (i) high power RF communications or backscattermodulation communications, (ii) AC powered or battery powered, and ifbattery powered, rechargeable, and (iii) inclusion, or not, ofsufficient processing and memory capability to also support a controllerfunction. The example handset 260 design contains the added advantage ofsupporting cordless phone functionality. Thus, the security network 400design can serve a dual purpose for users—security monitoring and voiceconversation—through a single network of base units 200. Thehandset-shaped base unit 200 with keypad 265 will typically be battery208 powered, with the battery 208 being rechargeable in a manner similarto existing cordless phones. One or more other base units 200 in thesecurity network 400 may contain gateway 300 functionality including aconnection to a telephone line 431, Ethernet 404, WiFi 404, or wireless402 network. Like all base units 200, the handset-shaped base unit 200with keypad 265 and the base units 200 with gateway 300 functionalitycan support high power RF communications with each other. The high powerRF communications can support voice conversation in addition toexchanging data for the operation of the security network 400.

The inventive security network 400 may include a mechanism to providealerts without calling the attention of an intruder to base units 200.One way in which this may be accomplished is a remote sounder 437. Aremote sounder 437 should be less expensive than a base unit 200 with anaudio transducer 210 because the remote sounder 437 contains only thefunctionality to receive commands from a base unit 200 and to providethe desired alert characteristics such as an audio siren. On exampleremote sounder 437 is shown in FIG. 26. This remote sounder 437 has beenconstructed in the shape of a lamp socket, such that (i) a light bulbmay be removed from a lamp socket, (ii) the remote sounder 437 isscrewed into the lamp socket, and then (iii) the light bulb is screwedinto the remote sounder 437. This example remote sounder 437 containsthe mechanical mechanism to (i) fit between a light bulb and a lampsocket, and (ii) pass AC power through the remote sounder, and also to(iii) obtain AC power from the lamp socket, (iv) receive communicationsfrom base units 200 using high power or low power RF communications, and(v) cause an audio siren when commanded by the master controller 251. Ifdesired, the remote sounder 437 may support two-way communications suchthat the master controller 251 may provide positive feedback from theremote sounder 437 that a message to alert or stop alerting has beenreceived. Alternately, if one or more base units 200 in a securitynetwork 400 contain an audio transducer 210 that can input audio, thenthe master controller 251 can receive feedback by commanding the one ormore base units 200 to determine whether the audio siren on the remotesounder 437 is generating audio volume that can be detected by the oneor more base units 200.

In addition to detecting intrusion, the security network 400 can monitorthe status of other environmental quantities such as fire, smoke, heat,water, gases, temperature, vibration, motion, as well as othermeasurable events or items, whether environmental or not (i.e.,presence, range, location). The list of sensor possibilities is notmeant to be exhaustive, and many types of sensors already exist today.For each of these sensor types, the security network 400 can beconfigured to report an alert based upon a change in the condition orquantity being measured, or by the condition or quantity reaching aparticular relationship to a predetermined threshold, where therelationship can be, for example, one or more of less than, equal to, ormore than (i.e., a monitored temperature is less than or equal to apredetermined threshold such as the freezing point).

These detection devices can be created in at least two forms, dependingupon the designer's preference. In one example embodiment, anappropriate sensor 620 can be connected to a transponder 100, in amanner similar to that by which an intrusion sensor 600 is connected tothe transponder 100. All of the previous discussion relating to thepowering of an LED generator 601 by the transponder 100 applies to thepowering of appropriate sensors 620 as well. This embodiment enables thecreation of low-cost sensors, as long as the sensors are within the readrange of base units 200.

In a second example embodiment, these sensor devices may beindependently powered, much as base units 200 and gateways 300 areindependently powered. Each of these detection devices are created bycombining a sensor appropriate for the quantity being measured andmonitored with a local power supply 264, processor 261, and acommunications mechanism 262 that may include high power RF orbackscatter modulation communications. These sensor devices may findgreat use in monitoring the status of unoccupied buildings, such asvacation homes. A temperature sensor may be useful in alerting a remotebuilding owner if the heating system has failed and the buildingplumbing is in danger of freezing. Similarly, a flood-prone building canbe monitoring for rising water while otherwise unoccupied.

The base unit 200 is typically designed to be inexpensively manufacturedsince in each installed security network 400, there may be several baseunits 200. From a physical form factor perspective, the base unit 200 ofthe present invention can be made in several embodiments. One embodimentparticularly useful in self-installed security networks 400 is shown inFIG. 13, where the packaging of the base unit 200 may have the plugintegrated into the package such that the base unit 200 is plugged intoa standard outlet 720 without any associated extension cords, powerstrips, or the like.

From a mechanical standpoint, one embodiment of the base unit 200 may beprovided with threaded screw holes on the rear of the packaging, asshown in FIG. 24A. If desired by the user installing the system of thepresent invention, holes can be drilled into a plate 722, which may bean existing outlet cover (for example, if the user has stylized outletcovers that he wishes to preserve) whereby the holes are of the size andlocation that match the holes on the rear of the packaging for the baseunit, for example. Alternately, the user can employ a plate in the shapeof an extended outlet cover 721 shown in FIG. 24B which providesadditional mechanical support through the use of additional screwattachment points. Then, as shown in FIGS. 24A and 24B, the plate 722 orcover 721 can be first attached to the rear of the base unit 200packaging, using the screws 724 shown, and, if necessary, spacers orwashers. The base unit 200 can be plugged into the outlet 720, wherebythe plate 722 or cover 721 is in alignment with the sockets of theoutlet 720. Finally, an attachment screw 723 can be used to attach theplate 722 or cover 721 to the socket assembly of the outlet 720. Thiscombination of screws provides positive mechanical attachment wherebythe base unit 200 cannot be accidentally jostled or bumped out of theoutlet 720. Furthermore, the presence of the attachment screw 723 willslow down any attempt to rapidly unplug the base unit 200.

In addition to the physical embodiments described herein, variouscomponents of the security network 400 can be manufactured in otherphysical embodiments. For example, modem outlet boxes used for bothoutlets and light switches are available in sizes of 20 cubic inches ormore. In fact, many modem electrical codes require the use of the theselarger boxes. Within an enclosure of 20 cubic inches or more, a baseunit 200 can be manufactured and mounted in a form integrated with anoutlet as shown in FIG. 23B or a light switch in a similarconfiguration. The installation of this integrated base unit 200 wouldrequire the removal of a current outlet, and the connection of the ACpower lines to the integrated base unit/outlet. The AC power lines wouldpower both the base unit 200 and the outlet. One or more antennas can beintegrated into the body of the base unit/outlet shown or can beintegrated into the cover plate typically installed over the outlet. Inaddition to a cleaner physical appearance, this integrated baseunit/outlet would provide the same two outlet connection points asstandard outlets and provide a concealed base unit 200 capability. In asimilar manner, an integrated base unit/light switch can also bemanufactured for mounting within an outlet box.

When the inventive security network 400 includes at least one gateway300 with modem functionality, it is advantageous for the securitynetwork 400 to seize the telephone line 431 if any other telephonydevice 455 (other than the security network 400 itself) is using thetelephone line 431 at the time that the security network 400 requiresuse of the telephone line 431. Furthermore, while the security network400 is using the telephone line 431, it is also advantageous for thesecurity network 400 to prevent other telephony devices 455 fromattempting to use the telephone line 431. Therefore, the securitynetwork 400 includes several ways in which to seize the telephone line455 as shown in FIG. 18.

A gateway 300 containing modem 310 functionality may include twoseparate RJ-11 connectors of the type commonly used by telephones, faxmachines, modems, and similar telephony devices. The first of the RJ-11connectors is designated for connection to the telephone line 431 (i.e.,PSTN 403). The second of the RJ-11 connectors is designated forconnection to a local telephony device 455 such as a telephone, faxmachine, modem, etc. The gateway 300 can control the connection betweenthe first and the second RJ-11 connector. The connection may becontrolled using a mechanical mechanism, such as a relay, or using asilicon mechanism such as a FET. When the security network 400 does notrequire use of the telephone line 431, the gateway 300 enables signalsto pass through the gateway 300 between the first and second RJ-11connector. When the security network 400 requires use of the telephoneline 431, the gateway 300 does not enable signals to pass through thegateway 300 between the first and second RJ-11 connector. In a securitynetwork 400 containing multiple gateways 300 with modem 310functionality, the security network 400 may command all gateways 300 tostop enabling signals to pass through each gateway 300 between therespective first and second RJ-11 connector of each gateway 300. Thus,all telephony devices 455 connected through gateways 300 to thetelephone line 431 may be disconnected from the telephone line 431 bythe security network 400.

In a home or other building, there may be telephony devices 455connected to the telephone line 431 that do not connect through agateway 300. This may be because there are simply more telephony devices455 in the home than there are gateways 300 in the home, for example.The inventive security network 400 may therefore include telephonedisconnect devices 435 that can be used by the security network 400 todisconnect a telephony device 455 from the telephone line 431 undercommand of the security network 400. One embodiment of the telephonedisconnect device 435 is shown in FIG. 26. In this example embodiment,the telephone disconnect device 435 includes a first male RJ-11connector and a second female RJ-11 connector. The design enables theexample telephone disconnect device 435 to be easily installed betweenan existing RJ-11 cord and an existing RJ-11 receptacle as shown. Otherembodiments are possible, such as an embodiment that includes both firstand second female RJ-11 connectors. The telephone disconnect device 435may obtain power from the telephone line 431 or may be battery powered.The telephone disconnect device 435 can control the connection betweenthe first and the second RJ-11 connector. The connection may becontrolled using a mechanical mechanism, such as a relay, or using asilicon mechanism such as a FET. When the security network 400 does notrequire use of the telephone line 431, the telephone disconnect device435 enables signals to pass through the telephone disconnect device 435between the first and second RJ-11 connector. When the security network400 requires use of the telephone line 431, the telephone disconnectdevice 435 does not enable signals to pass through the telephonedisconnect device 435 between the first and second RJ-11 connector. On astandard two-wire telephone line 431, such as those commonly used forPlain Old Telephone Service (POTS), it is not necessary for the gateway300 or the telephone disconnect device 435 to prevent signals frompassing on both wires in order to seize the telephone line 431.Typically, even if signals on only one of the wires of the two-wiretelephone line are enabled or not enabled, the gateway 300 or thetelephone disconnect device 435 can enable or prevent telephony devices455 from accessing the telephone line 431.

The telephone disconnect device 435 may obtain commands from thesecurity network 400 in any of several ways. For example, the telephonedisconnect device 435 may contain a wireless receiver by which toreceive high power or low power RF communications from any base unit200. In another example, the telephone disconnect device 435 may containan audio receiver by which to receive communications from a base unit200. It may be desired that the telephone disconnect device 435 beindividually addressable so that the security network 400 can sendcommands to selected telephone disconnect devices 435 withoutsimultaneously addressing all of the telephone disconnect devices 435.In this example, a base unit 200, typically a gateway 300, may send anaudio signal or a sequence of audio signals over the telephone lines ofthe house. These audio signals may be detected by the various telephonedisconnect devices 435 as commands to either enable or not enabletelephony signals to pass through the telephone disconnect devices 435.Typically, even though a telephone disconnect device 435 will not permitsignals to pass between the telephone line 431 and any telephony device455 connected to the telephone disconnect device 435, the telephonedisconnect device 435 will remain connected to the telephone line 431and may therefore continue to receive commands put onto the telephoneline 431 by a base unit 200. In this example, the term “audio tones” mayinclude frequencies that are outside of the normal hearing of a person.For example, most telephone systems are designed to support audio belowapproximately 4,000 Hz. However, the present invention may employ audioat higher frequencies such as 10 KHz, 20 KHz, or even higher. Since itis not necessary or even preferred for the telephone network tointerpret the audio tones sent from a base unit 200 to a telephonedisconnect device 435, there may be an advantage to using audio tones atfrequencies higher that those normally supported in the telephonenetwork.

The true scope of the present invention is not limited to the presentlypreferred embodiments disclosed herein. As will be understood by thoseskilled in the art, for example, different components, such asprocessors or chipsets, can be chosen in the design, packaging, andmanufacture of the various elements of the present invention. Thediscussed embodiments of the present invention have generally relied onthe availability of commercial chipsets; however, many of the functionsdisclosed herein can also be implemented by a designer using discretecircuits and components. As a further example, the base unit 200 andtransponder 100 can operate at different frequencies than thosediscussed herein, or the base units 200 can use alternate RFcommunications protocols. Also, certain functions which have beendiscussed as optional may be incorporated as part of the standardproduct offering if customer purchase patterns dictate certain preferredforms. Finally, this document generally references U.S. standards,customs, and FCC rules. Various parameters, such as input power oroutput power for example, can be adjusted to conform with internationalstandards. Accordingly, except as they may be expressly so limited, thescope of protection of the following claims is not intended to belimited to the specific embodiments described above.

1. A security network having a plurality of components for monitoring atleast a first opening for intrusion, the security network including: afirst controller function comprising both program code and configurationdata whereby each of the components are identified, enrolled, and placedunder control of the first controller function; and at least one secondcontroller function comprising both the program code and theconfiguration data, wherein the second controller function is inwireless communication with the first controller function and the firstand second controller functions share configuration data andcomponent-specific code or parameters.
 2. The security network of claim1, wherein the first controller function is the master controller forthe security network.
 3. The security network of claim 2, wherein if thefirst controller function fails, the second controller function becomesthe master controller.
 4. The security network of claim 2, wherein thefirst controller function ceases to be the master controller if thefirst controller function fails a self-test and the second controllerfunction becomes the master controller.
 5. The security network of claim1, wherein the first controller function includes means to arbitratewith the second controller function to determine which of them shall bethe master controller for the security network.
 6. The security networkof claim 1, wherein the first controller function sends a copy of itsconfiguration data to the second controller function.
 7. The securitynetwork of claim 1, wherein the first controller function is containedwithin a first base unit and the second controller function is containedwithin a second base unit.
 8. The security network of claim 1, whereinthe first controller function downloads software to the secondcontroller function.
 9. The security network of claim 1, furtherincluding a first transponder, wherein the first transponder transmits afirst transmitted message using wireless communications, the secondcontroller function receives a first received message, derived from thefirst transmitted message, and the second controller function sends thefirst received message to the first controller function.
 10. Thesecurity network of claim 1, wherein the first controller function iscontained within a first base unit located in a first building and thesecond controller function is contained within a second base unitlocated in a second building.
 11. The security network of claim 1,wherein the first controller function is contained within a first baseunit that is in a fixed location and the second controller function iscontained within a second base unit that is portable.
 12. The securitynetwork of claim 1, wherein the first controller function is containedwithin a first base unit that further includes a firsttelecommunications interface connected to a first telecommunicationsnetwork.
 13. The security network of claim 12, wherein the firstcontroller function relays a first message from the second controllerfunction to the first telecommunications network.
 14. The securitynetwork of claim 12, wherein the second controller function furtherincludes a first acoustic transducer capable of supporting audiocommunications, and wherein the first controller function relays theaudio communications from the first acoustic transducer to the firsttelecommunications network.
 15. The security network of claim 1, whereinthe first controller function receives a message from the secondcontroller function to cause an alert, and the first controller functioncauses an alert.
 16. The security network of claim 1, wherein the firstcontroller function uses a first encryption key to encryptcommunications sent to the second controller function.
 17. The securitynetwork of claim 1, wherein the first controller function uses a firstencryption key to authenticate communications sent to the secondcontroller function.
 18. The security network of claim 1, wherein thefirst controller function receives updated program code and (a) if thefirst controller function updates its program code and operatessuccessfully, then the second controller function receives the updatedprogram code, but (b) if the first controller function cannotsuccessfully update its program code and operate, then the firstcontroller function reverts to the previously stored program code.
 19. Asecurity network for monitoring at least a first opening for intrusion,the security network including: at least a first controller function anda second controller function, wherein the second controller function isin wireless communication with the first controller function; and afirst transponder, wherein the first transponder transmits a firsttransmitted message using wireless communications, the second controllerfunction receives a first received message, derived from the firsttransmitted message, and the second controller function sends the firstreceived message to the first controller function, and wherein the firstcontroller function receives a second received message, derived from thefirst transmitted message, and the first controller function combinesthe first received message and the second received message to produce athird received message.
 20. The security network of claim 19, whereinthe first controller function combines the first received message andthe second received message in a manner that reduces any errors betweenthe third received message and the first transmitted message.
 21. Asecurity network for monitoring at least a first opening for intrusion,including at least a first controller function and a second controllerfunction, wherein the second controller function is in wirelesscommunication with the first controller function and wherein the secondcontroller function receives wireless communications from the firstcontroller function and adjusts a timing means within the secondcontroller function based upon the wireless communications from thefirst controller function.